RUSOHEXTBHRaZH'S   SERIES. 

1'        iiOS'.S       .     NAT1    :     . 

OLOGY: 

OF 

SCHOOLS  AND  COLLEGES, 

B  V 

W.  S.  W.  RUSCHENBERGER,  M.D. 


in  the  U.  S.  ITavy ;  i'ellow  of  the  College  of  Physicians;   Hon. 

^dical  Society;  Meml- 
tural  Sciences  of  Philadelphia,  &c.  &c. 


FROM   THE  YtflvT.OF 

MILNE  EDWARDS,  AND  ACHILLE  COMTE, 

YKOFF.SSORS   OF   NATURAL  HISTORY  IN   THE  COLLEGES 
0?   HENRI   IV,    AND    CHARLEMAGNE, 

WITH    PLATES. 


PHILADELPHIA: 

GRIGG   &   ELLIOT, 

NO,  9   NORTH   FOURTH  STREET 

••.15. 


E.  FOOTE,  M.  D., 

adelphia,  Pa. 


BIOLOGY 

LIBRARY 

G 


RTJSCKENBERGER'S    SEHIES, 


FIRST  BOOKS  OF  NATURAL  HISTORY, 


ELEMENTS  OF  CONCHOLOGY: 

PREPARED  FOR  THE  USE  OF 

SCHOOLS  AND  COLLEGES, 

BY 

W.   S.   W.  RUSCHENBERGER,   M.D. 

Surgeon  in  the  U.  S.  Navy  ;  Fellow  of   the  College   of  Physicians  ;    Hon. 

Member  of  the  Philadelphia  Medical  Society  ;  Member  of  the 

Academy  of  Natural  Sciences  of  Philadelphia.  Sec.  &c. 

FROM    THE   TEXT   OF 

MILNE  EDWARDS,  AND  ACHILLE  COMTE, 

PROFESSORS    OF    NATURAL    HISTORY    IN   THE    COLLEGES 
OF    HENRI    IV,    AND    CHARLEMAGNE. 


•WITH     PLATES. 


PHILADELPHIA: 
GRIGG   &   ELLIOT, 

NO.   9   NORTH   FOURTH   STREET, 

1845. 


GY 


M 


,  according  to  the  Act  of  Congress,  in  the  year  1843,  by 
W.  S.  W.  RUSCHENBERGER,  M.D., 

in  the  clerk's  office  of  the  District  Court  of  the  United  States  in  and  for  the 
Eastern  District  of  Pennsylvania. 


?.  K.  k  P  G.  Collins,  Printers. 


(4) 


PREFACE. 


The  fifth  of  the  Series  of  First  Books  of  Natural  History,  em- 
braces that  branch  of  our  subject  which  treats  of  the  Mollusca, 
or  soft  animals,  and,  consequently,  includes  the  Elements  of  Con- 
chology. 

In  the  beauty  and  singularity  of  their  forms,  the  variety  and 
brilliancy  of  their  colours,  shells  only  yield  to  flowers.  The 
admiration  of  these  deserted  habitations  of  a  very  numerous  class 
of  animals  is  very  general,  if  not  universal ;  scarcely  a  house,  at 
least  in  sea-port  towns,  is  without  a  few  shells,  and  in  many  there 
are  large  collections  of  them.  Comparatively,  few  persons,  how- 
ever, view  them  in  connection  with  animal  existence — for  the 
mass,  they  are  merely  beautiful  things  from  the  seas  and  rivers, 
far  and  near.  We  care  little  how  they  grow,  how  they  live,  how 
they  breathe,  upon  what  they  feed,  or  for  what  use  they  were 
created.  Who  stops  to  think  an  oyster  has  a  heart  and  blood- 
vessels, a  breathing  apparatus,  a  nervous  system,  or  digestive 
organs  ?  How  very  few  are  aware  that  certain  snails  possess 
eyes  and  lay  eggs ;  nor  is  it  universally  known  that  we  are  in- 
debted to  the  organization  of  soft  animals  for  mother-of-pearl  and 
pearls ! 

Limited  as  this  little  volume  is,  it  may  prove  a  key  to  stores 
of  information,  even  more  interesting  to  many  than  the  numerous 
fictions  of  the  day.  "  Truth  is  stranger  than  fiction,"  has  been 
often  said ;  and  the  beautiful  truths  brought  to  us  by  a  study  of 
animal  life,  in  its  various  forms,  are  certainly  more  admirable  and 
wonderful  than  any  fiction  of  man's  creation. 

Is  there  any  thing  produced  by  the  Bulwers  or  the  James'  of 
the  day,  more  worthy  of  admiration  than  the  habits  of  a  snail, 
or  the  movements  of  a  cockle-shell?  When  at  the  Sandwich 
Islands,  in  1836,  we  heard  an  anecdote  which  has  an  application 
here.  The  officers  of  a  British  ship  of  war  manifested  a  strong 
desire  to  obtain  "  curiosities  :"  a  young  Kanaka,  with  a  view  to 


6  PREFACE. 


profit,  brought  to  one  of  these  officers  a  chicken's  foot,  and 
offered  it  for  sale ;  and  by  way  of  insisting  upon  its  value,  said, 
as  he>  pulled  the  tendon  which  was  attached  to  its  toes,  "  See  how 
nicely  it  works ;"  and  was  it  not  more  worthy  of  attention  and 
thought  than  all  the  idols  of  wood  and  stone  that  could  be  col- 
lected? 

Fictions  are  the  works  of  man,  but  the  wonderful  truths  of  the 
universe  are  the  creations  of  Omnipotence ;  yet  we  bestow  more 
time  and  more  interest  on  the  last  novel,  in  many  instances,  than 
would  be  sufficient  to  lead  us  to  the  contemplation  of  all  the  beau- 
tiful and  magnificent  productions  which  it  was  Adam's  duty  to 
name.  Whoever  reveres  his  God,  should  be  able  to  contemplate 
his  works  understandingly,  and  be  able  to  perceive  the  beauty  of 
design,  the  adaptation  of  the  organization,  the  various  forms  of 
life,  to  the  circumstances  in  which  life  is  placed,  and  perceive  the 
same  wise  hand  in  the  structure  of  the  snail,  as  in  the  complete 
and  perfect  animal,  man ;  and  learn  too,  that  even  an  oyster  is 
within  the  scheme  and  protection  of  Providence. 

In  forming  this  little  volume,  besides  the  works  of  MM.  Ed- 
wards and  Comte,  those  of  Cuvier,  Lamarck,  Blainville  and  Cap- 
tain Thomas  Brown  have  been  consulted  and  freely  used. 

Many  of  the  engravings  are  copied  from  the  works  of  M.  Blain- 
ville ;  and,  it  is  believed,  the  engraving,  which  was  done  by  Mr. 
G.  Thomas,  (No.  37  South  Third  Street,)  will  compare  favour- 
ably with  anything  of  the  kind  ever  offered  to  the  American 
public. 

The  etymology  and  pronunciation  of  the  technical  words  have 
been  placed  at  the  foot  of  the  page. 

This  little  volume  offers  the  means  of  becoming  acquainted 
with  the  history  of  soft  animals  and  conchology,  and  opens  the 
way  to  an  advantageous  perusal  of  more  complete  and  ample 
treatises  on  the  subject. 

Philadelphia,  June  1,  1844. 


CONCHOLOGY. 


CONTENTS. 


LESSON  I. 

General  Considerations.  —  Mollusca  in  general  —  Organization — Nervous 
System— General  Form— Skin— Mantle — Shell — Formation  of  Shell — 
Digestive  Apparatus — Circulation  of  the  Blood — Respiration — Senses 
— Eggs — Classification. 

LESSON  II. 

Class  of  Cephalopoda. — General  Form — Respiration — Circulation— Organa 
of  Digestion — Cephalic  Cartilage— Organs  of  Locomotion — Organs  of 
the  Senses — Nervous  System — Habits — Division  into  two  Families. 

Family  of  Cephalopoda  Dibranchiata. — Octopus  Vulgaris,  or  Poulpe — Argo- 
naut— Calmaries — Cuttle-fishes. 

Family  of  Cephalopoda  Tetrabranchiata. — Nautilus — Ammonites — Belem 
nites — Foraminifera. 

LESSON  III. 

Class  of  Gasteropoda. — General  Conformation — Classification. 

Order  of  Gasteropoda  Pulmonea. — Organization — Division  into  two  Families. 

Family  of  Terrestrial  Pulmonea. — Limax — Vaginulus — Helix — Bulimus— 

Pupa — Chondrus — Clausilia — Achatina. 
Family  of  Aquatic  Pulmonea. — Onchidium — Planorbis — Limnaea — Physa— 

Auricula. 

Order  of  Gasteropoda  Pectinibranchiata. — Organization — Classification. 
Family  of  Trochoides.— Trochus— Turbo— Delphmula— Turritella— Cyclo- 

stoma — Valvata — Paludina — Littorina — Monodon — Phasianella — Am. 

pullaria — Janthina — Nerita. 

LESSON  IV. 

Family  of  Buccinoides. — Buccinum — Buccinum  properly  so  called — Harpa 
— Purpura — Cassis — Cerithium — Murex — Strombus — Voluta — Ovula 
Cyprsea — Conus. 

Family  of  Pectinibranchiata  Capuloida. — Pileopsis — Hipponyx — Crepidula 
— Calyptraea — Siphonaria — Sigaretus. 

Order  of  Gasteropoda  Tubulibranchiata. 

Order  of  Gasteropoda  Scutibranchiata. — Haliotis— Fissurella — Emarginula. 


8  CONTENTS. 


Order  of  Gasteropoda  Cyclobranchiata. — Patella — Chiton. 

Order  of  Gasteropoda  Inferobranchiata. 

Order  of  Gasteropoda  Tectibranchiata. — Pleurobranclms — Aplysia — Dola- 

bella— Bullea— Bulla. 

Order  of  Gasteropoda  Nudibranchiata. — Eolidia — Glaucus. 
Order  of  Gasteropoda  Heteropoda. — Carinaria. 
Class  of  Mollusca  Pteropoda. — Clio  borealis. 

LESSON  V. 

Class  of  Mollusca  Acephala,  or  Lamellibranchiata. — Organization — Classi- 
fication. 

Family  of  Ostracea. — Classification — Oysters — Gry  phaea — Pecten — Lima- 
Malleus — Anomia — Spondy  lus — Perna — Etheria — Avicula — Pearls- 
Pearl  Fishery — Pinna — Area — Pectunculus — Trigonia. 

Family  of  Mytilacea. — Mussels,  (Mytilus) — Modiolus — Anodonta — Unio. 

Family  of  Chamacea. — Tridacna — Chama — Isocardia. 

LESSON  VI. 

Family   of  Cardiacea. — Cardium — Donax — Cyclas — Corbis — Tellina — Ve« 

nus — Petricola — Venerupis — Mactra. 
Family  of  Inclusa.  —  Lutraria  —  Mya — Byssomia — Hiatelia — Solen — San- 

guinolaria — Pholas — Teredo — Fistulana — Gastrochaena — ClavigelJa— 

Aspergillurn. 
Class  of  Mollusca  Brachiopoda. — General  Characters — Lingula — Terebra- 

tula — Orbicula. 
Class  of  Mollusca  Tun icata,  or  Acephala  Nuda. — Biphora — Ascidia — Botryl- 

lus — Pyrosoma — Parts  of  Shells. 


ELEMENTS  OF  CQyCHOLOGY. 

SECOND    BRANCH   OF   THE   ANIMAL   KINGDOM. 


MOLLUSC  A: 

MOLLUSKS,  OR  SOFT  ANIMALS. 


LESSON  I. 

GENERAL  CONSIDERATIONS. — Mollusca  in  general — Organiza- 
tion— Nervous  System — General  Form  —  Skin  —  Mantle — 
Shell — Formation  of  Shell — Digestive  Apparatus — Circula- 
tion of  the  Blood — Respiration — Senses — Eggs — Classifica- 
tion. 

The  long  series  of  vertebrate  animals,  the  history  of  which  we 
have  already  concluded,  forms  only  a  small  part  of  the  animal 
kingdom,  and  to  make  the  beings  we  are  now  about  to  study  as 
interesting  as  the  vertebrata,  we  should  be  obliged  to  very  far 
exceed  the  limits  of  these  lessons :  but  these  animals  are  less 
useful  to  us ;  they  attract  less  attention,  and  most  of  them  pass 
unnoticed,  except  by  those  who  are  at  the  pains  of  becoming  ac- 
quainted with  them ;  their  faculties  are  more  limited  and  their 
structure  is  less  complicated  and  less  perfect. 

1.  All  these  lower  animals  want  a  spinal  marrow  and  a  true 
internal  skeleton ;  this  last  character  has  obtained  for  them  the 
collective  name  of  invertebrate  animals  ;  but  in  a  natural  classi- 
fication, they  could  not  all  be  placed  in  the  same  group,  because 
they  are  evidently  formed  after  three  different  types,  and  there- 
fore should  be  divided  into  three  distinct  branches,  namely  :  the 
mollusca,  the  articulata^  the  radiata,  or  zoophytes. 

2.  The  branch  of  zoophytes  is  composed  essentially  of  the 
most  imperfect  animals  :  according  to  the  classification  of  Cuvier, 
which  we  follow,  this  branch  comprises  a  certain  number  of  beings 
which  seem,  in  a  manner,  to  present  the  first  sketch  of  the  mode 
of  organization  proper  to  mollusks  and  articulate  animals ;  its 
place  is  therefore  among  the  lowest  grades  of  the  animal  series, 
and  passes,  by  gradual  shades,  from  the  type  of  the  radiate  ani- 
mal to  that  of  the  two  great  branches  which  spring  from  it.    These 
two  latter  branches,  one  equally  with  the  other,  present  a  con- 
stantly increasing  complication  of  organization,  and  form,  as  it 

1.  What  are  inver'tebrate  animals  ?     What  groups  or  divisions  include 
the  inver'tebrate  animals  ? 

2.  What  are  zo'ophytes  ?     Why  are  the  mollus'ca  placed  before  the  artlc- 
ulata  in  the  series  of  animals  ? 

9 


10  NERVES  O'F  MOLLUSKS. 

were,  two  p^rallex  series.  The  series  of  articulate  animals  seems 
to  be  the  highest  in  the  scale;  but  the  mollusca,  though  less  per- 
fect in  structure,  seem  to  be  less  remote  in  their  mode  of  orga- 
nization from  the  vertebrata,  and  for  this  reason  we  have  deter- 
mined to  place  them  first. 

3.  We  give  the  name  of  Mollusca  (from  the  Latin,  mollis, 
soft)  to  animals  which,  in  the  general  features  of  their  orga- 
nization,  resemble  snails,  oysters,  &c.     They  have  no  articu- 
lated skeleton  nor  vertebral  canal,  like  the  vertebrate  animals  ; 
their  body  is  soft,  and  their  skin,  which  is  often  covered  by  a 
shell,  is  never  hardened  so  as  to  form  a  kind  of  external  skele- 
ton composed  of  a  series  of  rings,  as  is  the  case  in  insects  and 
the  Crustacea. 

4.  The  nervous  system,  an  apparatus  of  so  much  importance, 
the  action  of  which  regulates  all  the  phenomena  of  animal  life, 
and  the  functions  of  which  must  necessarily  be  in  harmony  with 
its  mode  of  conformation,  differs  altogether  in  the  mollusca  in 
its  general  disposition,  from  what  we  observe  in  the  vertebrata. 
There  exists  a  nervous  centre  which  to  a  certain  extent  may  be 
compared  to  the  brain  in  superior  animals ;  but  this  ganglionic 
mass  is  not  continuous  with  an  organ  analogous  to  the  spinal 
marrow  ;  the  other  central  parts  of  the  nervous  system  are  found 
on  the  opposite  side  of  the  digestive  tube,  and  hence  this  canal  is 
always  embraced  by  a  sort -of  medullary  collar,  from  which  the 
different  nerves  of  the  body  arise.     In  other  respects,  this  appa- 
ratus varies  more  in  its  arrangement  than  in  the  number  of  parts 
composing  it. 


Fig.  1. NERVOUS    SYSTEM    OF    A    SOLEN. 

5.  In  a  great  many  of  the  least  perfect  mollusks,  such  as  the 
Solen  and  many  other  acephala,  which  inhabit  bivalve  shells, 
the  nervous  system  is  generally  composed  of  but  two  pairs  of 
ganglia,  united  by  two  long  inter-ganglionic  cords,  giving  rise 
to  different  branches  (fig.  1);  the  ganglia  of  the  anterior  pair 

Explanation  of  Fig.  1. — Nervous  system  of  an  acephalous  mollusk 
(Solen) : — a,  the  pair  of  ganglia  which  is  situate  in  front  of  the  oesophagus 
representing  that  portion  of  the  nervous  system  of  these  animals,  which  is 

3.  What  are  the  general  characters  of  the  Mollus'ca  ? 

4.  What  are  the  peculiarities  of  arrangement  of  the  nerves  of  the  Mollus'ca? 

5.  What  are  the  general  characters  of  the  nervous  system  in  acephalous 
mollusks  ?    What  are  tnc  peculiarities  of  the  nervous  system  of  gasteropods? 


NERVES  OF  MOLLUSKS. 


11 


Fig.  2. 

NERVES    OF   A 
JANTHINA. 


(a)  are  sometimes  considerably  separated  from 
each  other,  and  only  united  by  an  intermediate 
cord,  and  sometimes  glued  one  to  the  other,  or 
even  confounded  in  a  single  mass :  they  are 
situate  above  the  O3sophagus,  and  far  from  the 
posterior  ganglia  (6),  which  are  placed  beneath 
the  intestine  towards  the  posterior  part  of  the 
body.  In  some  mollusks,  the  nervous  system 
is  still  more  simple  in  its  composition  ;  but,  in 
general,  the  ganglia  tend  to  approximate  the 
oesophagus  more  and  more  (Jig-  2),  and  in 
most  of  these  animals  we  find  a  greater  num- 
ber of  small  medullary  masses,  some  of  which 
form  a  sort  of  nervous  centre,  and  the  others 

are    distributed    in     different    parts 

of  the    body.     Thus,    in   the  snails 

and   most    mollusks   constructed  on 

the  same  plan,  and  named  gastero- 

pods     (from    the     Greek,     gaster, 

belly,  and  pous,  foot),   on   account 

of  their   mode   of  crawling  on  the 

ventral   surface  of  the   body,    there  g  — 

exists,   above   and    in    front   of   the  p  "' 

oesophagus,  a  medullary  mass  (Jig. 

3,  c.),  which   is   the    representative  d  — 

of    the    anterior    pair    of    ganglia 

above    mentioned,  and  which  is  re-  a"" 

garded    by    most   anatomists   as  the     Fig.  3.— NERVES  OF  A  SNAIL. 

generally  called  the  brain  ;  here,  these  two  ganglia  are  considerably  sepa- 
rated from  each  other,  and  are  united  by  a  transverse  band  ;  —  c.  nerves 
which  arise  anteriorly  to  be  distributed  to  the  tentacula,  to  the  mantle,  &c. ; 
— 6.  ventral  pair  of  ganglia,  which  are  united  in  a  single  mass,  placed  be- 
neath  the  intestine,  and  joined  to  the  anterior  ganglia  by  two  very  long 
nervous  cords  ; — d.  nerves  which  arise  from  the  posterior  ganglia  to  t>e  dis- 
tributed to  the  mantle,  &c. 

Explanation  of  Fig.  2. — Nervous  system  of  a  Janthina  ;  a  gasteropod 
mollusk,  in  which  the  posterior  ganglia  (&)  as  well  as  the  anterior  ganglia 
(a)  are  separated  from  each  other ;  but  they  are  more  approximated  to  the 
latter,  so  that  the  inter-ganglionic  cords  are  very  short,  and  form  a  sort  of 
closely  fitting  collar  around  the  oesophagus. 

Explanation  of  Fig.  3. — Central  portion  of  the  nervous  system  of  the 
snail : — c.  ganglia  situate  in  front  of  the  oesophagus,  and  constituting,  by 
their  union,  the  mass  which  is  called  the  brain  in  mollusca ; — o.  nerves  of 
the  anterior  parts  of  the  body,  the  eyes,  &c. ; — g.  the  nervous  mass  formed 
by  the  union  of  the  ganglia  of  the  posterior  pair ;  the  oesophagus  passes 
through  the  collar  or  ring  which  unites  it  to  the  brain ; — p.  the  nerves  of 
the  foot ; — n.  nerves  which  go  to  the  pulmonary  cavity,  &c. ; — a.  the  nerve 
which  accompanies  the  principal  artery ; — d.  the  nerve  which  goes  to  the 
diaphragm,  &c. 


12 


NERVES  OF  THE  APLYSIA. 


brain  of  these  animals  :  it  furnishes  nerves  to  the  organs  of 
the  senses  as  well  as  to  the  neighbouring  parts  (o),  and  is 
continued  posteriorly  by  two  inter-ganglionic  cords,  which  em- 
brace the  oesophagus,  and  which,  at  a  short  distance,  unite 
with  a  second  nervous  mass  (g),  situate  beneath  the  digest- 
ive tube,  and  comparable  to  the  posterior  pair  of  ganglia, 

which  we  remarked  when 
speaking  of  the  acephalous 
mollusks ;  and  two  small 
nerves,  which  arise  from  the 
brain,  unite  to  form  a  third 
ganglion  (fig.  4,  *),  below 
the  origin  of  the  O3sophagus. 
c  In  other  gasteropods,  the 
o  aplysice  or  sea-hares,  for  ex- 
ample, to  these  ganglia  is 
g  joined  another  (fg.  4,  v),  si- 
tuated among  the  viscera, 
and  united  by  two  commu- 
nicating threads  to  the  med- 
ullary collar  which  surrounds 
the  oesophagus,  and  giving 
rise  to  the  nerves  of  the  in- 
testines, liver,  branchiae,  ova- 
ries, &c.  We  also  find  in 
these  mollusks  a  fifth  gan- 
glion, which  is  very  small, 
belonging  to  these  tatter  or- 
gans. And,  in  the  poulpes 
and  the  cuttle-fish  (fg.  5). 
A  /  /^^^^\  " v  in  which  this  system  acquires 

/          \f/f'        V  its  hishest  degree  °r  de- 

velopmerit,  the  ganglionic 
parts  grouped  around  the 
oesophagus,  are  larger  and 
more  complicated ;  for  the 
I  cephalic  and  post-oosopha- 

geal    ganglia,  united    in    a 

Fig.  4.— NERVES  OF  THE  ArLYsiA.        large     cEsophageal      collar, 

present     laterally    a     third 


Explanation  of  Fig.  4. — Nervous  system  of  the  aplysia  (or  sea-hare,  as 
it  was  called  by  the  ancients),  another  gasteropod  mollusk  ; — c.  the  brain  ; — 
o.  the  nervous  collar  which  surrounds  the  oesophagus  ; — g.  the  thoracic  of 
post-cesophageal  ganglia  ; — v.  the  visceral  ganglion ; — t.  the  buccal  ganglion. 


NERVES  OF  MOLLUSKS. 


13 


pair  of  ganglionic 
swellings,  which 
are  lodged  in  a 
cartilaginous,  cra- 
nial cravity  ,•  from 
them  arise  the 
nerves  of  the  feet 
(Fig.  5). 

To  recapitulate, 
we  see  that,  in  this 
class  of  animals, 
the  nervous  sys- 
tem is  essentially 
composed  of  a 
medullary  collar, 
embracing  the  ali- 
mentary tube,  and 
formed  by  the 
communicating 
cords  of  the  two 
pairs  of  ganglia, 
which  are  widely 
separated  in  the 
acephalous  mol- 
lusks,  but  approx- 
imate more  and 
more  as  we  ascend 
in  the  series,  form- 
ed by  the  gaster- 
opods  and  cepha- 
lopods ;  and  the 


Fig.   5. NERVOUS   SYSTEM  OF   THE   CUTTLE-FISH. 


Explanation  of  Fig.  5. — Nervous  system  of  the  cuttle-fish  ; — a,  the  ner- 
vous collar  which  embraces  the  oesophagus,  the  course  of  which  is  indi- 
cated by  a  bristle  (s): — c,  the  nervous  mass,  situate  .in  front  of  the  eesophagus, 
and  commonly  called  the  brain  :  the  upper  surface  is  surmounted  by  a  very 
large  cordiform  tubercle,  and  from  its  anterior  part  arise  two  nerves  that 
soon  terminate  in  a  circular  ganglion,  which,  in  its  turn,  gives  rise  to 
another  pair  of  nerves,  which  descend  beneath  the  mouth  so  as  to  embrace 
the  oesophagus  again,  and  then  form  a  small  anterior  ganglion  from  which 
arise  the  labial  nerves ; — &.  the  tentacular  ganglia,  from  which  arise  the 
nerves  of  the  arm  ; — o.  the  optic  nerves  which  arise  from  the  lateral  parts 
of  the  brain,  and  soon  swell  into  a  large  ganglion  ; — t.  small  nervous  tuber- 
cles, situate  on  the  origin  of  the  optic  nerves ; — g.  the  sub-cesophageal  or 
ventral  ganglion; — c.  the  great  nerve  of  the  viscera,  one  branch  of  which 
presents  an  elongated  ganglion  (r\  and  penetrates  into  the  branchiae  ; — fit 
nerves  which  also  arise  from  the  post-oasophageal  ganglia,  and  which,  in 
their  course,  present  a  large  star-like  ganglion  (e),  the  branches  of  which 
are  distributed  to  the  mantle. 
2 


14  FORM.— SKIN.—SHELI . 

nerves  which  arise  from  each  of  these  ganglia,  to  be  distributed 
to  the  different  organs*,  are  at  first  simple,  but  very  soon  pre- 
sent in  different  parts  of  the  body  ganglionic  swellings ;  but 
these  ganglia,  however  numerous  they  may  be,  never  form  a  reg- 
ular longitudinal  chain,  extending  along  the  middle  line  of  the 
abdominal  face  of  the  body,  as  is  the  case  in  the  articulated  ani- 
mals. 

6.  As  we  have  already  said,  in  this  great  branch  of  the  animal 
kingdom,  there  is  neither  an  internal  skeleton,  analogous  to  the 
solid  frame  of  vertebrate  animals,  nor  an  external  skeleton,  sim- 
ilar to  the  tegumentary  sheath,  which  envelopes  the  whole  body 
of  articulate  animals  in  a  series  of  rings,  and  serves  the  same 
purposes  as  the  skeleton,  properly  so  called,  of  the  superior  ani- 
mals.     The  general  form  of  mollusks  is  extremely  variable. 
Their  body  is  always  soft,  and  in  a  very  small  number  of  them 
only,  there  exists  internally  some  solid  pieces  which  are  unarticu- 
lated,  and  serve  rather  to  protect  the  viscera  than   to  furnish 
levers  and  points  of  support  to  the  apparatus  of  locomotion.    The 
muscles    are  attached  directly  to  the  integuments  and  act  but 
very  little  beyond  their  point  of  insertion  ;  their  motions  are  slow, 
and  in  general  ill  directed.     In  a  small  number  of  these  beings, 
there  are  elongated  and  flexible  appendages,  designed  for  locomo- 
tion (fg.  7,  page  23) ;  but  in  most  instances  the  animal  can 
change  its  place,  only  by  successively  contracting  different  points 
of  the  inferior  surface  of  its  body,  and,  even  when  it  possesses 
extremities,  they  are  united  in  a  group  at  one  end  of  the  body, 
and  never  arranged  in  a  symmetrical  series,  as  they  are  inverte- 
brate and  in  articulate  animals. 

7.  The  skin  of  mollusks,  always  soft  and  viscid,  often  forms 
folds  that  more  or  less  completely  envelope  the  body,  and  this 
disposition  has  caused  the  name  of  mantle  to  be  given  to  that 
portion  of  integument  which  ordinarily  furnishes  these  expansions. 
Frequently  this  mantle  or  pallium  is  almost  entirely  free,  and 
constitutes  two  large  veils  which  conceal  all  the  rest  of  the  ani- 
mal, or  rather,  these  two  laminae  or  membranes  unite  together  so 
as  to  form  a  kind  of  tube ;  but  at  other  times,  it  consists  only  of 
a  sort  of  dorsal  disk,  the  edges  of  which  alone  are  free,  or  sur- 
round the  body  more  exactly  under  the  form  of  a  sack. 

8.  In  general  this  soft  skin  is  protected  by  a  sort  of  stony 
cuirass  named  shell.     It  is  a  secretion  having  some  analogy  to 

6.  What  kind  of  a  skeleton  have  mollusks  ?     What  are  the  g-eneral  cha- 
racters of  their  body  ?     How  is  locomotion  effected  in  molliasks  ? 

7.  What  is  the  mantle  or  pallium? 

8.  What  is  meant  by  shell  ?     What  is  meant  by  naked  mollusks  ?    What 
are  testacea  ? 


GROWTH  OF  SHELLS.  15 

that  of  the  epidermis  which  produces  this  envelope.  The  follicles, 
ordinarily  lodged  in  the  edges  of  the  mantle,  deposit  upon  its 
surface  a  semi-corneous  matter,  mixed  with  a  greater  or  less  pro- 
portion of  carbonate  of  lime,  which  moulds  itself  upon  the  sub- 
jacent parts  and  solidifies.  The  lamina  or  layer,  thus  formed, 
thickens  and  grows  by  successive  deposits  of  new  matter.  Its 
superficies  is  not  stony,  but  in  form  of  a  kind  of  epidermis. 
Sometimes  it  preserves  a  horny  consistence  throughout  its  whole 
thickness.  In  general,  however,  the  proportion  of  carbonate  of 
lime  that  it,  contains  rapidly  increases  and  imparts  to  it  a  stony 
hardness.  The  internal  surface  is  often  harder  than  the  rest, 
and  possesses  a  particular  structure  which  renders  it  vitreous  or 
shining  and  nacreous.  Sometimes  the  shell  always  remains  en- 
closed in  the  thickness  of  the  skin  ;  but,  in  general,  it  is  external, 
and  extends  beyond  the  mantle,  so  as  to  aiford  the  animal  perfect 
protection.  Those  which  are  unprovided  with  shells,  or  only 
have  an  internal  shell,  are  called  naked  mollusks,  and  those  in 
which  the  shell  is  visible  are  included  under  the  name  of  con- 
chifera,  or  sometimes  testa' cea. 

9.  The  manner  in  which  the  shell  grows  is  easy  to  under- 
stand.    If  we  examine  the  shell  of  an  oyster,  for  example,  we 
observe  that  it  consists  of  a  multitude  of  superposed  laminae,  the 
separation  of  which  may  be  effected  by  the  assistance  of  heat._ 
These  laminre  are  formed  successively  by  the  mantle  of  the  ani- 
mal which  they  cover,  and,  consequently,  the  most  external  one 
must  be  the  oldest ;  and  it  is  also  the  smallest,  and  each  new 
lamina  that  is  added,  exceeds  the  lamina  situate  above,  so  that 
while  the  shell  is  augmenting  in  thickness,  it  is  also  increasing  in. 
size.     In  general,  the  distinctness  of  the  lamina  is  less  marked^* 
and  often  the  new  matter  is  deposited  in  such  a  manner,  that  its 
molecules    exactly  correspond  to   the    molecules  of  the  matter 
already  consolidated,   and  thus  gives    to    the   whole  a   fibrous 
structure. 

10.  Shells  are  adorned  with  most  diversified  and  most  agree- 
ably arranged  colours,  which  often  vary  with  their  age.     They 
are  almost  always  entirely  superficial,  and  seem  to  depend  on  a 
sort  of  a  dyeing  process  performed  by  the  skin  of  the  animal, 
which  is  coloured  in  a  manner  corresponding  with  that  of  its  en- 
velope.    The  colouring  matter  seems  to  be  deposited  upon  the 
shell  at  the  time  of  its  formation  :  and  its  brightness  is  in   pro- 
portion to  the  newness  of  the  latter.     It  is  produced  by  the  edge 
of  the  mantle.     When  a  shell  happens  to  be  broken  and  the  ani- 


9.  How  does  the  shell  grow  ? 
10.  How  are  the  colours  of  shells  produced  ? 


16  COLOURS.  OF  SHELLS. 

mal  succeeds  in  repairing  the  accident,  the  part  newly  formed  ia 
always  white,  if  it  has  not  been  in  contact  with  the  edge  of  the 
mantle ;  but  if  it  correspond  to  this  edge,  it  then  assumes  the 
colour  that  the  latter  presents  at  the  point  touched.  For  exam- 
ple, when  this  edge  is  spotted,  we  find  corresponding  spots  on 
the  margin  of  the  shell,  and,  in  proportion  as  the  latter  is  elon- 
gated, these  spots  become  confounded  with  those  previously 
formed,  and  produce  lines  perpendicular  to  crossing  strite,  or 
they  do  not  join  the  latter,  but  remain  isolated,  according  as  the 
mantle  remains  unmoved,  and  preserves  the  same  relation  to  the 
margins  of  the  shell,  or 'frequently  changes  its  position  according 
to  the  movements  of  the  animal.  Sometimes  the  secretion  of 
the  colouring  matter  varies  with  age;  and  accidental  circum- 
stances may  also  modify  it.  Light,  for  example,  exerts  a  very 
remarkable  influence  on  this  phenomenon,  for  not  only  are  shells 
that  are  most  exposed  to  the  action  of  this  physical  agent,  ordi- 
narily most  brightly  coloured,  but,  when  a  mollusk  lives  fixed  to 
a  rock,  or  in  some  spot  hidden  beneath  a  sponge,  or  other  opaque 
body,  the  part  of  the  shell  thus  placed  in  darkness  is  always 

/  dull,  and  paler  than  that  which  is  exposed  to  the  contact  of  th® 
solar  rays. 

The  duration  of  shells,  and  the  length  of  time  the  animals  live 

i  which  inhabit  them,  are  circumstances  not  yet  determined.  When 
exposed  to  the  action  of  the  air  and  the  vicissitudes  of  tempera- 
ture and  moisture  for  some  time,  shells  usually  change  their 
colours  and  gradually  become  white.  The  animal  matter  which 
enters  into  its  composition  is  destroyed,  and  disappears  little  by 
little ;  the  laminre  separate  from  each  other,  particularly  under 
the  alternate  influence  of  heat  and  cold,  and  become  finally  re- 
duced to  a  calcareous  powder,  which  is  washed  away  by  currents 
of  water. 

11.  All  mollusks  are  provided  with  an  alimentary  canal,  which 
is  more  or  less  folded  on  itself  and  open  at  its  two  ends,  either  at 
the  extreme  points  of  the  body,  or  at  points  more  or  less  near  to 
each  other.     There  is  always  a  voluminous  liver,  and  we  often 
find  them  furnished  also  with  salivary  glands  and  organs  of  mas- 
tication ;  but  the  intestines  are  never  held  in  their  place  by  the 
assistance  of  a  mesentery. 

12.  The  blood  of  these  animals  is  cold  and  colourless  or  slightly 
bluish,  and  circulates  in  a  very  complicated  vascular  apparatus, 
composed  of  arteries  and  veins.  A  heart,  formed  of  a  ventricle  (v) 

11.  What  are  the  general  characters  of  the  digestive  apparatus  of  mol- 
lusks  .' 

12.  What  is  the  nature  of  the  blood  of  mollusks  ?    How  is  it  circulated  ? 


CIRCULATION— SENSES. 


17 


and  one  or  two  auricles  (o) 
is  found  in  the  track  of  the 
arterial  blood,  and  sends 
this  liquid  to  all  parts  of 
the  body,  from  which  it  re- 
turns to  the  organs  of  respi- 
ration. Sometimes  we  also  r 
find,  at  the  base  of  the  ves- 
sels which  enter  this  latter 
apparatus,  venous  reser- 
voirs, erroneously  called  pul- 
monary hearts  ;  for,  having 
nothing  in  their  structure  re- 
sembling muscle,  they  can- 
not set  the  blood  in  motion, 
and  consequently  do  not  me- 
rit this  name.  (See  Jig.  9, 
Page  21.) 

13.  The  organs  of  respira- 
tion vary  so  much  that  they 
cannot   be  well  described  at 
this   place :  we    will    merely 
mention  that  they  are  some- 
times in  the    form  of  lungs, 
and    at    others,    in  that    of 
branchiae  or  gills. 

14.  Nor  can  we  say  any  thing  generally  of  the  structure  of 
the  organs  of  the  senses,  which  are,  however,  always  less  com- 
plete than  in  the  vertebrate  animals.     Certain  mollusks  appear  to 
be  endowed  only  with  the  sense  of  touch  and  with  the  sense  of  taste, 
but  in  a  great  many  we  find  eyes  which  vary  in  structure,  and 
in  some  of  these  animals  there  even  exists  an  apparatus  of  hear- 
ing :  but  none  is  known  to  possess  a  particular  organ  of  smell. 

15.  Mollusks  are  re-produced  from  eggs;  but  are  sometimes 
hatched  without,  and  sometimes  within  the  body  of  the  mother, 


Fig.  6. HEART    OF    AN  ACEPHALOUS 

3IOLLUSK. 


Explanation  of  Fig-  6. — Heart  of  an  acephalous  mollusk  : — v.  the  ventri- 
cle, which  in  these  animals  has  the  rectum  (r)  passing  through  it,  and 
gives  rise  to  two  arteries  (a)  ; — c.  one  of  the  auriculo-ventricular  openings  ; 
— o.  the  two  auricles  receiving  the  blood  from  the  branchial  veins  (&)• 

In  the  above  diagram,  the  ventricle  (?>)  is  open,  and  the  rectum,  (r,  r) 
has  been  divided,  and  the  lower  part  turned  downwards  : — a  (at  the  lower 
part  of  the  figure)  represents  the  origin  of  one  artery,  the  other  artery 
having  a  similar  origin  above. 

1 3.  What  is  the  character  of  the  organs  of  respiration  in  mollusks  ? 

14.  What  senses  are  possessed  by  mollusks  ? 

15.  How  are  mollusks  re-produced  ? 

2* 


IB 


CLASSIFICATION. 


and  then  the  young  are  born  alive.  In  all  cases  they  possess  at 
birth  nearly  the  form  they  preserve  through  life,  and  do  not  un- 
dergo metamorphosis. 

We  have  already  stated  that  mollusks  differ  very  much  in  the 
general  form  of  their  body,  and  as  these  external  modifications 
are  accompanied  by  corresponding  differences  in  the  degree  of 
complication  of  their  internal  organization,  they  enable  us  to  di- 
vide these  animals  into  six  natural  groups.  The  following  table 
will  give  an  idea  of  this  classification : 

(CLASSES.) 

in  the  form  of  an  open  sack  in  front,  from  ) 
which  the    head    appears,  surrounded  by  >  CEPHALOPODA. 
tentacula  (Fig.  7,  Page  19).  ^ 


f  having  a 

distinct 

head,  and 

the  body 


not  in  the  form  of  an  f  membranous  fins  in 
open  sack  in  front,   I  the  form  of  wings 
and  the  head  is  not  |  on  the  sides  of  the 
surrounded  with  ten-  I  neck, 
tacula. 

•  a  fleshy  foot   occu-' 


T> 

PTEROPOI)A' 


pying    the     ventral 


having  no 

apparent  •> 

head 


the  principal  organs 
.of  motion  being 


disk,  or   sometimes 
^of  fins. 

having   four   branchiae   distinct   from  the 
mantle,  and  almost  always  a  fleshy  foot. 

having  no  fleshy  foot  f"  provided    with  two 
and  seldom  branchiae 
distinct    from     the 
mantle. 


A 


of  them.  J   ' 

unprovided      with   ) 

arms   and    special   >  TUNICATA. 

organs  of  motion.    } 

Cuvier,  and  many  other  zoologists,  arrange  the  cirrhopoda  also 
in  the  branch  of  mollusca ;  but  it  is  now  ascertained  that  these 
animals  belong  to  the  branch  of  articulata,  the  third  great  divi- 
sion of  the  animal  kingdom. 


16    Into  how  many  classes  is  the  branch  of  mollus'ca  divided? 


CLASS  OF  CEPHALOPODS.  .  19 

LESSON  II. 

CLASS  OF  CEPHALOPODA. — General  Form — Respiration — Cir- 
culation —  Organs  of  Digestion  —  Cephalic  Cartilage  — 
Organs  of  Locomotion —Organs  of  the  Senses  —  Nervous 
System — Habits — Division  into  two  Families. 

FAMILY  OF  CEPHALOPODA  DIBRANCHIATA. —  Octopus  vulgaris, 
or  Poulpe — Argonaut — Calmaries — Cuttle-Jishes. 

FAMILY  OF  CEPHALOPODA  TETRABRANCHIATA.  —  Nautilus  — 
Ammonites — Belemnites — Foraminafera. 

CLASS  OF  CEPHALOPODS, 

1.  This  class  is  composed  of  mollusks  which  are  of  fantastical 
shape,  for  their  head  is  placed  between  the  trunk  and  feet,  or 
tentacula,  which  serve  them  for  locomotion,  and  when  they  walk, 
the  body  is  uppermost,  and  the  head  down,  dragging  on  the 
ground.  Their  feet  are  attached,  around  the  mouth,  to  the  head, 
which  circumstance  has  obtained  for  them  the  name  of  Cephalo- 
poda (from  the  Greek,  Tcephole,  head,  and  pous>  foot  —  pro- 
nounced Jcef-a-lo-pod). 


Fig.  7. — OCTOPUS*    VULGARIS, — OR    COMMON    POULPE. 

2.  The  trunk  of  these  animals  is  covered  by  the  mantle, 
which  is  in  the  form  of  a  sack,  sometimes  almost  spherical, 
and  sometimes  more  or  less  elongated ;  it  encloses  all  the 

*  From  the  Greek,  okto,  eight,  and  pous,  foot, — eight  feet. 


1.  What  kind  of  animals  compose  the  class  of  Cephalopods  ?     Why  are 
sy  called  Cephalopods  ? 

2.  What  are  the  general  form  and  characters  of  the  Cephalopods  ? 


20 


STRUCTURE  OF  CEPHALOPODS. 


* 


viscera  and  is  open  only  in  front,  (Jig.  8,  o).  The  head  issues 
from  this  opening :  it  is  round  and  generally  provided  with  two 
round  eyes,  very  analogous  in  their  structure  to  those  of  verte- 
brate animals.  The  mouth  occupies  the  centre  :  it  is  armed 
with  two  jaws ;  and  around  this  opening  is  found  a  crown  of 
flexible  and  fleshy  appendages,  which  are  termed,  indifferently, 
legs  or  arms,  because  they  seem  to  be  entitled  to  either  appella- 
tion ;  for  they  serve  both  as  organs  of  prehension  and  locomo- 
tion (fi.g.  7). 

3.  The  cephalopods  are  essentially  aquatic  animals,  and 
consequently  they  breathe  by  means  of  branchiae.  These 
organs  are  always  perfectly  symmetrical,  and  are  found  con- 
cealed beneath  the 
mantle,  in  a  particu- 
lar cavity  (fig.  8),  the. 
parietes  of  which  alter- 
nately contract  and  di- 
late, and  the  interior 
communicates  exter- 
nally by  two  openings ; 
one  (o)  in  form  of  a 
slit,  serving  for  the 
entrance  of  the  water, 
and  the  other  pro- 
longed in  the  shape  of 
a  tube  or  funnel  (/), 
serving  for  the  escape 
of  water  and  excre- 
ment. Each  branchia 
(6),  which  is  in  form 
of  an  elongated  pyra- 
mid, the  summit  of 
which  is  directed  forward,  is  composed  of  a  great  number  of 
membranous  lamella  or  leaves,  placed  transversely  and  fixed 
on  each  side  of  a  middle  stalk.  Each  one  of  these  leaves  is 
divided  into  lamella?,  which  are  in  turn  again  subdivided,  and 
it  is  in  their  substance  that  we  find  the  capillary  vessels  where 


Fig.  8. BODY    OF    A    POULPE. 


Explanation  of  Fig.  8.— The  body  of  a  poulpe  seen  from  beneath  (the 
mantle  is  slit  up  on  the  middle  line,  and,  on  one  side,  raised  up  to  show  the 
interior  of  the  respiratory  cavity) :— a.  the  base  of  the  head ; — t.  the  tube 
by  which  the  water  escapes  from  the  respiratory  cavity ; — o.  one  of  the  two 
lateral  openings  through  which  the  water  enters  this  cavity  ; — b.  one  of  the 
branchiae  or  gills. 


3.  How  do  cephalopods  breathe  ?  How  many  branchise  have  cephalopods  1 


CIRCULATION  IN  CEPHALOPODS. 


21 


the  venous  is  changed  into  arterial  blood.  The  number  of 
branchiae  varies,  and  this  difference  is  characteristic  of  the  two 
great  natural  divisions,  of  which  this  class  is  composed.  In 
some  there  is  but  a  single  pair,  while  in  others  two  pairs  of 
branchiae  are  found.  For  this  reason  the  first  have  been  called 
cephalapoda  dibranchiata  (from  the  Greek  dis,  two,  and 
bragchos,  branchia  or  gills, — two-gilled),  and  the  last,  cephalo- 
poda tetrabranchiata  (from  the  Greek,  tetras,  four,  and  bragchos, 
branchia,— four-gilled). 

4.  The  heart  is  situated  between  the  branchise  on  the  middle 
line  of  the  body,  and  consists  only  of  a  single  ventricle 
(fg.  9,  c)  :  the  blood  reaches  it  from  the  branchiaB  by  the 


br 


vv      av      a     cs       vv 

Fig.  9. ORGANS  OF  CIRCULATION  AND  RESPIRATION  IN  THE  CUTTLE-FISH. 

Explanation  of  Fig.  9. — The  organs  of  circulation  and  respiration  of  the 
cuttle-fish  ; — c.  the  aortic  heart,  the  upper  extremity  of  which  is  continuous 
with  the  superior  aorta,  which  distributes  the  blood  to  the  head,  &c. ; — 6. 
branches  of  this  vessel ; — a.  the  inferior  aorta,  which  has  a  bulb  at  its  origin, 
and  soon  divides  into  two  branches  (w,  D)  ; — vc.  the  vena  cava,  the  parietes 
of  which  are  covered  by  the  spongy  bodies  (cs) ; — av.  veins  of  the  viscera, 
going  to  empty  into  the  two  branches  of  the  vena  cava ; — cb,  venous  sinus 
or  branchial  heart ; — s.  swelling  at  the  base  of  the  branchial  arteries ; — br. 
branchia?  ; — ab.  branchial  artery  ; — vl.  branchial  vein  ; — bu.  bulb  of  the 
branchial  veins,  situate  near  the  termination  of  these  vessels  in  the  heart, 


4.  What  is  the  character  of  the  heart  in  cephalopods  1    What  are  the 
peculiarities  of  the  circulation  1 


22  CIRCULATION  IN  CEPHALOPODS. 

branchial  veins  (vb),  the  openings  of  which  are  furnished  with 
valves,  and  then  penetrates  the  arteries  which  arise  from  this 
organ.  The  latter  vessels  are  two  or  three  in  number  ;  but  one 
of  them  is  always  much  larger  than  the  rest,  and  one  of  them 
also  has  at  its  base  a  swelling  or  bulb,  which  is  more  or  less 
muscular,  and  analogous  to  that  found  at  the  origin  of  the  aorta 
in  batrachians.  The  great  artery  to  which  we  generally  give  the 
name  of  aorta,  is  carried  forward  and  distributes  its  branches  to 
a  part  of  the  viscera,  the  head  and  legs.  The  other  arteries  go 
to  the  viscera  ;  and  the  blood,  after  having  in  this  way  passed 
through  all  the  organs,  returns  by  the  veins,  and  is  emptied  by 
them  into  a  great  vena  cava,  situate  near  the  heart.  The  bran- 
chial arteries  arise  from  the  inferior  extremity  of  this  last  vessel, 
and,  in  the  dibranchial  cephalopods,  present  a  very  remarkable 
arrangement ;  for,  before  penetrating  the  branchia?,  each  one  of 
them  dilates  so  as  to  form  a  great  venous  sinus  (Jig*  9,  c&), 
which  most  authors  regard  as  a  branchial  heart,  but  its  parietes 
do  not  appear  to  be  really  muscular. 

5.  We  see,  therefore,  that  the  circulation  is  here  carried  on  in 
a  manner  opposite  to  that  of  fishes  ;  for  the  heart  is  found  in  the 
track  followed  by  the  arterial  blood,  while  in  fishes  the  venous 
blood  passes  through  this  organ  ;  but  in  other  respects,  there  is 
a  great  resemblance  in  the  general  disposition  of  the  circulatory 
apparatus  of  these  two   classes  of  animals  ;  for,  in   both,  the 
blood   passes   but  once  through  the  heart,  and  the  whole  of  it 
traverses  the  respiratory  apparatus  before  returning  to  the  differ- 
ent organs. 

6.  On  the  vena  cava  and  its  principal  branches,  we  remark  a 
multitude  of  very  singular  spongy   bodies  (fig-  9,  <*s),  which, 
when  squeezed,  yield  a  mucosity,  and  which  are  attached  to  the 
parietes  of  these  vessels ;  these  appendages  are  enclosed  in  two 
membranous  pouches,  which  perform  the  functions  of  a  pericar- 
dium, and,  at  the  same  time,  communicate  by  particular  openings 
with  the  branchial  cavity.     In  this  way  the  water  from  without 
laves  them,  and  their  interior,  which  is  hollow,  communicates  by 
other  holes  with  the  interior  of  the  veins,  so  that  the  blood  must 
enter  them.     We  know  nothing  certain  in  regard  to  their  uses; 
but  it  is  probable  they  are  the  seat  of  some  secretion,  and  that 
they  serve  as  a  reservoir  to  contain  the  superabundant  blood  of 
the  veins,  when  the  circulation  is  interrupted  in  the  vessels,  much 
in  the  same  manner  as  the  spleen  seems  to  do  in  the  superior 
animals. 


5.  How  does  the  circulation  in  cephalopods  differ  from  that  of  fishes  ? 

6.  What  is  remarkable  about  the  vena  cava  ? 


DIGESTION  IN  CEPHALOPODS. 


23 


7.  The  apparatus  of  digestion  is  very  complicated.  The 
mouth  is  surrounded  by  a  circular  lip,  and  armed  with  two  ver- 
tical mandibles,  which  closely  resemble  the  beak  of  a  parrot ; 
they  are  set  in  motion  by  powerful  muscles.  A  fleshy  tongue, 
furnished  with  papillae  and  many  horny  pieces,  occupies  the  in- 
terior of  this  cavity,  and  is  attached  to  a  particular  cartilage. 
Salivary  glands,  the  number  and  arrangement  of  which  vary  a 
little,  surround  the  pharynx  and  oesophagus,  and  pour  into  the 
alimentary  canal  the  product  of  their  secretion.  The  oesopha- 
gus contracts  in  general,  and  before  terminating  in  the  stomach, 
presents  a  large  dilatation  or  crop  (Jig.  10,  j) ;  but  some- 
times, this  first 
digestive  pouch  is 
wanting.  Com- 
monly the  stom- 
ach is  in  the  form 
of  an  elongated 
sack  ;  its  parietes 
are  muscular,  and 
its  structure  re- 
minds  us  of  the 
gizzard  of  birds. 
A  third  cavity  (s)  ' 
succeeds  this  or-  as 
gan,  which,  in  di- 
branchial  cepha- 
lopods,  is  in  the  1 
form  of  a  coecum 
spirally  folded, 
while  in  the  tetra- 
branchial,  it  as- 
sumes that  of  a 
spherical  sack  in- 
ternally lamella- 


•br 


a    v 


cb~ 


Flg.  10. — VISCERA   OF   A    POULPE. 


Explanation  of  Fig.  10. — Viscera  of  a  poulpe  : — j.  the  crop  situated  be- 
neath  the  cephalic  cartilage  ; — gs.  inferior  salivary  glands  ;— /.  mass  formed 
by  the  liver  and  ink-bag  ; — e.  excretory  duct  of  the  ink-bag  going  to  empty 
in  the  funnel ; — t.  this  funnel  or  tube  ; — m.  the  open  mantle  ; — s.  the  ccecum 
spirally  folded  ; — i.  a  part  of  the  intestine,  the  rest  being  removed  to  show 
the  organs  situate  beneath  ; — o.  the  oviducts  ; — c.  the  heart ; — a.  the  inferior 
aorta  ; — as.  the  superior  aorta  ; — vb.  the  branchial  veins  ; — br.  the  branchiae ; 
— cl.  the  partition  by  which  these  organs  adhere  to  the  parietes  of  the  re- 
spiratory  cavity  ; — ab.  the  branchial  arteries  ; — cb.  venous  sinus  or  branchial 
hearts  ; — v.  venae  cavae  ;—fm.  muscular  fasciculi. 

7.  What  organs  constitute  the  apparatus  of  digestion  in  cephalopods  ? 
What  is  remarkable  about  the  mouth  ?  What  is  the  character  of  the 
stomach  ?  What  is  the  nature  of  the  liver  ? 


24  ORGANS  OF  LOCOMOTION. 

ted  :  the  bile  is  poured  into  this  cavity  by  two  canals.  The 
liver  is  very  voluminous,  sometimes  simple,  and  sometimes  di- 
vided into  two  or  more  lobes :  its  colour  is  reddish  yellow,  and 
its  texture  very  soft.  The  intestine,  which  arises  very  near  the 
cardiac  orifice,  is  simple,  and  communicates,  at  a  short  distance 
from  the  pylorus,  with  a  glandular  pouch  which  seems  to  be  ana- 
logous to  the  pancreas ;  and,  after  making  several  curves,  this 
tube  empties  into  the  branchial  cavity,  at  the  base  of  the  funnel 
through  which  the  water  escapes  that  has  served  the  purposes  of 
respiration. 

8.  In  dibranchial  cephalopods,  there  exists  in  the  neighbour- 
hood of  the  liver  another  very  remarkable  secretory  organ,  which 
produces  in  abundance  a  blackish  liquid,  called  ink  ;  the  excre- 
tory duct  of  this  gland  (fig.  10,  e)  empties -into  the  intestine  near 
its  extremity,  and,  when   the  animal  is  in  danger,  pours  out, 
through  the  funnel  or  tube,  enough  of  this  liquid  to  darken  the 
water  around,  and  thus  conceal  itself  from  the  sight  of  its  ene- 
mies.    The  ink  of  one  of  these  cephalopods — the  cuttle-fish — is 
employed  in  painting,  under  the  name  of  sepia ;  and  many  au- 
thors suppose  that  the  Indian  ink  of  the  Chinese  is  an  analogous 
substance,  though  it  appears  the  material  commonly  used  in  the 
manufacture  of  Indian  ink  is  nothing  but  very  finely  powdered 
charcoal.     The  tetrabranchial  cephalopods  do  not  possess  any- 
thing similar. 

9.  It  has  been  already  stated  that  mollusks  have  no  solid,  ar- 
ticulated frame  within  their  body,  similar  to  the  skeleton  of  ver- 
tebrate animals.     In  the  cephalopods,  however,  we  find  traces  of 
something  analogous;   for  there  exists  in  the  head  a  cartilage 
which  not  only  protects  the  brain,  but  enlarges  the  head  in  differ- 
ent directions,  to  furnish  points  of  insertion  to  the  principal  mus- 
cles of  the  animal. 

10.  The  disposition  of  the  organs  of  locomotion  and  prehen- 
sion, which  are  fixed  around  the  mouth,  varies  in  these  animals. 
In  the  dibranchial  cephalopods,  there  is  a  crown  of  eight  or  ten 
large  fleshy  tentacula,  the  inferior  surface  of  which  is  furnished 
with  suckers,  like  cupping-glasses,  by  aid  of  which  they  fix  them- 
selves very  strongly  to  bodies  that  they  embrace  (see  fig.  7,  page 
19).     In  the  tetrabranchial  cephalopods,  on  the  contrary,  these 
appendages,  though  very  numerous,  are  slender  and  unprovided 
with  suckers. 

11.  The  organs  of  the  senses  are  most  perfect  in  the  dibran- 


8.  What  is  sepia  ?     How  is  it  formed  ?     What  is  Indian  ink  ? 

9.  Have  cephalopods  anything  resembling  an  internal  skeleton  ? 
10.  What  is  the  disposition  of  the  organs  of  locomotion? 


SENSES  OF  CEPHALOPODS.  25 

chial  cephalopods.  In  these  mollusks  there  are  two  very  large 
eyes  of  spheroidal  form,  lodged  in  the  lateral  parts  of  the  head. 
These  organs  are  composed  of  a  transparent  cornea,  let  into  the 
skin,  and  sometimes  protected  by  a  fold,  like  an  eyelid,  a  crystal- 
line lens,  a  vitreous  body,  a  retina,  a  choroid  coat,  a  sclerotica, 
&c.,  nearly  the  same  as  in  vertebrate  animals.  In  the  tetrabran- 
chial  cephalopods  the  eyes  are  borne  on  projecting  peduncles,  and 
consist  of  a  cavity  only,  the  black  interior  of  which  contains  a 
retina,  and  receives  the  luminous  rays  through  a  circular  open- 
ing. No  auditory  apparatus  has  yet  been  discovered  in  the  first 
of  these  two  families.  We  find  in  the  cephalic  cartilage  of  the 
latter,  two  small  cavities,  closed  on  all  sides,  except  at  the  point 
through  which  the  nerve  penetrates ;  they  lodge  a  membranous 
vesicle,  and  are  filled  with  a  peculiar  fluid,  containing  a  small 
stone.  This,  as  we  see,  is  a  still  more  simple  arrangement  than 
that  of  fishes ;  for  the  whole  apparatus  is  reduced  to  a  vestibule 
and  a  nerve  only. 

12.  The  nervous  system  of  the  cephalopods  is  more  compli- 
cated than  that  of  the  other  mollusks,  and  the  different  ganglia, 
grouped  around  the  oesophagus,  have  a  greater  tendency  to  be- 
come confounded  in  a  single  mass.  The  medullary  collar,  thus 
formed,  is  composed  of  three  pairs  of  ganglia,  namely :  the 
cephalic  ganglia  (fig.  11,  c),  the  tentacular  ganglia  (£),  and  the 
thoracic  ganglia  (g) ;  the  two  first  pairs  are  placed  above  the 
oesophagus,  and,  by  joining  the  first,  form  a  double  collar  around 
this  tube;  sometimes  they  are  very  distinct,  but  at  others,  they 
are  almost  entirely  confounded.  The  cephalic  ganglia  give  rise 
laterally  to  two  large  nervous  cords,  which,  from  their  origin, 
enlarge  into  ganglia,  and  then  furnish  the  optic  nerves ;  from 
this  species  of  brain,  nerves  also  arise,  which  go  to  the  mouth, 
and  sometimes  form  around  this  opening  a  new  collar,  fur- 
nished with  two  pairs  of  small  ganglia  (fig-  5,  page  13).  The 
tentacular  ganglia  afford  origin  to  the  nerves  of  the  feet  or  ten- 
tacula,  which,  before  ramifying  on  these  organs,  also  present 
ganglionic  swellings.  Finally,  the  thoracic  ganglia,  sometimes 
very  distinct  from  the  preceding,  and  at  others  confounded  with 
them  (see  fig.  6,  page  17),  furnish  many  nerves,  the  most  import- 
ant of  which  are,  1st,  The  two  nerves  of  the  viscera  (fig.  11,  fl), 
which  in  their  course  present  a  pair  of  ganglia  and  distribute 
their  branches  to  the  branchiae,  the  heart,  stomach,  &c. ;  2d,  The 
nerves  of  the  mantle,  which,  in  the  dibranchial  cephalopods, 


11.  Where  are  the  eyes  situated  in  cephalopods?     Are  cephalopods  ca- 
pable of  hearing  ? 

12.  What  is  the  general  character  of  the  nervous  system  of  cephalopoda ' 

3 


26 


NERVES  OF  CEPHALOPODS. 


also  terminate  in  ganglia, 
from  which  arise  a  great 
many  filaments.  In  the  tetra- 
branchial  cephalopods,  the 
cesophageal  collar  is  simply 
protected  by  the  cephalic  car- 
tilage; but  in  the  dibranchial 
cephalopods,  in  which  the 
nervous  system  acquires  its 
highest  degree  of  develop- 
ment, this  medullary  mass 
is  lodged  in  a  special  cavity, 
hollowed  in  the  cartilage 
through  which  the  oesopha- 
gus passes. 

13.  The  cephalopods  are 
never  hermaphrodite,  as  are 
most  others  of  the  mollusca. 
The  ovary  is  always  simple 
and  lodged  at  the  bottom  of 
a  sac  formed  by  the  body  of 
the  animal ;  sometimes  there 
is  but  a  single  oviduct ;  at 
others,  we  find  two,  which 
open  at  the  base  of  the  fun- 
nel ;    finally,  all  these  ani- 
mals are  oviparous. 

14.  All    these   mollusks 
are  marine :  they  are  very 
voracious,  and  feed  chiefly 
on    crustacea    and     fishes, 

which  they  seize  by  the  aid  of  their  supple  and  vigorous  arms, 
and  easily  devour  by  means  of  their  sharp  mandibles.  Their 
flesh  is  eaten. 

15.  This  class  is  divided  into  two  families. 


Fig,  11. NERVOUS    SYSTEM    OF 

THE    NAUTILUS. 


Explanation  of  Fig.  11. — Nervous  system  of  the  Nautilus  : — c.  the  brain; 
— o.  the  optic  nerves  ; — g.  the  sub-cesophageal  or  thoracic  ganglia  ; — f.  the 
tentacular  ganglia ; — p.  nerves  of  the  tentacula  ; — e.  the  nerves  of  the  funnel ; 
— a.  a  ganglion  from  which  arise  other  tentacular  nerves  (ft) ; — d.  a  second, 
and  similar  ganglion,  also  giving  rise  to  tentacular  nerves  (/) ; — m.  nerves 
of  the  mantle,  &c. — v.  the  great  visceral  nerves,  each  of  which  gives  rise  to 
a  ganglion  (gv~),  from  which  the  principal  nerves  of  the  viscera  take  their 
origin. 

13.  Do  cephalopods  lay  eggs? 

14.  Where  are  cephalopods  found  ?     Upon  what  do  they  feed  ? 

15.  How  is  the  class  of  cephalopoda  divided  ? 


DIBRANCHIAL  CEPHALOPODS.          27 

16.  The  family  of  CEPHALOPODA,  DIBRANCHIATA, — or  ACE- 
TABULI'FERA, — that  is,  cupping-glass  bearers,  is  very  numerous. 
In  it  are  placed  the  poulpes,  cuttle-fishes,  calmaries,  argonauts, 
&c.     Most  of  these  mollusks  have  no  external  shell,  and  their 
naked  skin  includes  a  great  number  of  contractile  vesicles,  filled 
with  differently  coloured  fluids,  which,  by  alternately  contracting 
and  expanding,  produce  and  cause  again  to  disappear,  in  turn, 
often  very  brilliant  spots;  but  we  find  in  their  interior  a  more  or 
less  developed  shell,  situated  on  the  back.     This  shell  is  largest 
in  the  cuttle-fishes ;  it  is  oval,  and  composed  for  the  most  part  of 
a  great  number  of  transverse  calcareous  laminaB  ;  it  is  very  com- 
mon on  the  sea-shore,  and  is  generally  known  under  the  name 
of  cuttle-fish  bone.    In  the  calmaries  it  is  of  a  horny  consistence, 
and  in  its  form  resembles  a  feather  or  lamella ;  and  in  the  poul- 
pes it  is  merely  represented  by  two  horny  stylets,  lodged  in  the 
thickness  of  the  mantle. 

17.  The  tentacula  of  these  cephalopods  form  a  simple  crown 
around  the  mouth,  and  bear  on  their  internal  face  circular  cups 
or  suckers,  the  number  of  which  varies  from  eight  to  ten.     In 
the  following  family  we  shall  find  an  entirely  different  arrange- 
ment. 

18.  The  POULPES — Octopus  (Fig.  7,  Page  19) — are  easily 
recognised  by  their  naked   body,  which   is  in   the  form  of  an 
oval  sack,  unprovided  with  fins,  and  their  eight  very  large  and 
nearly  equal    feet.     They  make   use   of  these    last   organs    to 
seize  their  prey  as  well  as  to  swim  and  crawl  upon- the  ground, 
and  are  even  formidable  to  swimmers  on  account  of  the  force 
with  which  they  press  those  bodies  they  embrace.     These  ani- 
mals are  essentially  carnivorous.     Their  size  is  often  very  great : 
there  is  one  species  in  the  Pacific  Ocean  which  attains   about 
six   feet  in   length.     These  mollusks  are   objects   of  terror   to 
the  natives  of  the  Polynesian  Islands,  who  dive  to  the  bottom 
of  the  sea  for  shells;  but  their  size  and  strength  are  wonder- 
fully exaggerated.     Pliny  speaks  of  a   poulpe  that    had   arms 
thirty  feet   long;    and   a   modern    author   gravely   relates   the 
history  of  one  of  these  gigantic  mollusks,  which,  attacking  a 
vessel,  nearly  upset  it !     The  Common  Poulpe — Sepia  Octopo- 
dia — is  about  two  feet  long ;  it  inhabits  the  coasts  of  Europe, 
and  commonly  keeps  among  rocks :  it  destroys  a  great  many 
fishes  and  Crustacea. 


16.  What  are  the  general  characters  of  the  cephalopoda  dibranchiata  ? 
What  is  cuttle-fish  bone  ? 

17.  How  are  the  tentacula  of  cephalopods  arranged? 

18.  What  are  the  general  characters  of  the  poulpes  ?    What  is  the  nature 
of  their  food  ?    Where  are  they  found  ? 


28 


ARGONAUTS. 


Fig.  12. — ARGONAUT. 

19.  The  ARGONAUTS — Argonauta  (Fig.  12) — are  cephalopods 
very  closely  allied  to  the  poulpe,  but  the  pair  of  feet  which  is 
nearest  the  back  is  dilated  at  the  extremity  into  a  broad  mem- 
brane,  and  the  body  is  always  lodged  in  a  very  delicate  and  ex- 
tremely beautiful  shell,  vulgarly  called  the  paper  nautilus.  It  is 
not  certainly  known,  however,  whether  this  shell  really  belongs 
to  the  animal  that  inhabits  it,  or  whether  it  is  derived  from  some 
other  rnollusk.  Be  this  as  it  may,  the  cephalopod  does  not  ad- 
here to  it,  but  uses  it  as  a  boat  to  float  on  the  surface  of  the  water 

19    What  are  the  general  characters  of  the  argonaut  ? 


CALM  ARIES— CALM  A  RETS. 


29 


when  the  sea  is  calm.  Six  of  its  tentacula  are  then  folded  be- 
neath and  act  as  oars,  and  it  is  pretended  that  the  two  others, 
the  extremities  of  which  are  enlarged  and  raised  up,  are  spread 
for  sails,  as  represented  in  the  figure  (12)  ;  but  we  should  not 
infer  from  their  structure  that  these  tentacula  are  adapted  to  such 
a  purpose.  The  common  species  is  found  in  the  Mediterranean, 
the  Indian  Ocean,  &c. ;  it  was  known  to  the  ancients  under  the 
name  of  nautilus,  and  pompilius. 

20.  The  CALMAKIES — Loligo — differ  from  the  preceding  in  their 
elongated  sack,  and  being  provided  with  two  terminal  fins,  by  the 
horny  lamina,  lodged  in 
the  back,  which  supplies 
the  place  of  shell,  and  by 
their  tentacula,  which  are 
ten  in  number,  and  not 
of  the  same  configura- 
tion throughout  (fg.  13).  *•  13— THE  COMMON 
Eight  of  these  feet  are  of  moderate  size,  and  are  armed  with  little 
cups  in  their  whole  length,  while  the  two  others  are  very  much 
elongated  and  have  cups  only  near  their  extremities. 

21.  TheCALMAHETS Lo- 

ligopsis — are  remarkable  for 
the  great  length  of  two  of  their 
arms  (fg.  14),  which  are  fili- 
form, and  widened  at  the  end 
only ;  in  other  respects  they 
differ  but  little  from  the  Cal- 
maries  :  they  are  found  in  the 
Mediterranean. 

22.  Certain    cephalopods, 
which  resemble  the  Calmaries 
very  much,    but   have   their 
long     arms    furnished    with 
hooks,    form   the    genus    of 
Onychoteuthis  (from    the 
Greek  onux,  in  the  genitive 
onuchos,  nail,  and  teuthis,  a 
calmary,  that  is,  a  calmary 
with  nails. 

23.  The    CUTTLE-FISHES 
Fig.  14.— THE  CALMARET.            — Sepia— have  the  tentacular 

20.  How  do  the  Calmaries  differ  from  the  Argonauts  ? 

21.  What  are  Calmarets? 

22.  What  is  the  ony'choteuthis  ?  (pronounced  o-ni-ko-tu-this.) 

23.  What  are  the  general  characters  of  the  cuttle-fish  ?     Of  what  use  is 
cuttle-fish  bone  ? 


30  CUTTLE-FISHES.— NAUTILUS. 

appendages  arranged  like  the  calmaries;  but  their  body,  which 
is  oval  and  depressed,  is  furnished  with  fleshy,  lateral  fins,  occu- 
pying the  whole  length  of  the  sack,  and  the  back  is  sustained  by 
a  large  internal  shell,  the  structure  of  which  has  been  already 
mentioned.  The  species  most  commonly  found  in  the  seas  of 
Europe — Sepia  officinalis — attains  a  foot  in  length  or  more. 
The  cuttle-fish  bone  or  shell,  in  powder,  is  used  as  a  dentifrice, 
and  is  employed  in  the  arts  for  several  purposes,  as  for  polishing, 
for  forming  moulds  for  silver  castings,  and  as  a  pounce. 

24.  The  family  of  CEPHALOPODA  TETRABRANCHIATA  has  for 
its  type  the  NAUTILUS,  a  very  remarkable  mollusk,  the  body  of 
which  is  enclosed  in  the  last  chamber  (a)  of  a  large  shell,  folded 

spirally,  and  divided  by  transverse 
partitions  (b)  into   several  cavities, 
(Jig.  15).     Each  one  of  these  par- 
titions is  pierced  by  a  hole,  and  the 
canal  thus  formed,  which  is  called 
the  syphon  (s),  extends  to  the  pos- 
terior extremity  of  the  shell;  it  is 
traversed    by   a    contractile   mem- 
branous tube,  posterior  to  the  body 
of    the    animal.       This    structure 
b    c        seems  designed  to  facilitate  the  as- 
Fig.  15. — SECTION  OF  A         cent  or  descent  of  the  animal  in  the 
NAUTILUS.  water,  by  increasing  or  diminishing 

the  specific  gravity  of  the  shell  ;  for  the  syphon  communicates 
with  an  external  reservoir,  and  can  empty  or  distend  itself  with 
the  water  found  in  it ;  now,  the  chambers  which  it  passes  through 
are  filled  with  air,  and  when  this  tube  becomes  inflated,  it  must 
compress  this  elastic  fluid,  and  increase  its  density,  which,  at  the 
same  time,  augments  the  specific  gravity  of  the  whole  shell,  and 
must  give  it  a  tendency  to  sink  towards  the  bottom  of  the  water 
in  which  it  floats. 

25.  The  conformation  of  the  animal  differs  very  much  from 
that  of  the  poulpes,  calmaries,  and  other  dibranchial  cephalopods. 
The  head  of  the  nautilus  is  surrounded  by  a  large  fleshy  disk, 
which  bears  some  analogy  to  the  foot  of  the  gasteropods,  and 

Explanation  of  Fig.  15.— Vertical  section  of  the  nautilus  shell : — a.  the 
last  chamber,  in  which  the  animal  is  lodged  ;— 6.  one  of  the  partitions  which 
divides  the  chambers  (c)  from  each  other  j — s.  the  syphon. 

24.  What  are  the  peculiarities  of  the  nautilus  shell  ?     What  seems  to  be 
the  object  of  this  peculiar  structure  ? 

25.  How  is  the  animal  of  the  nautilus  characterized  ? 


AMMONITES. 


31 


probably  serves 
the  animal  in 
crawling.  The 
tentacula,  \vhich 
are  inserted  near 
the  mouth,  are 
not  furnished 
with  cups  as  in 
the  preceding 
family  :  they  are 
retractile  and  in 
considerable 
number.  The 
eyes  are  pedun- 
culate, that  is, 
supported  on  a 
sort  of  foot-stalk 
or  stem  :  there 
is  no  organ  of 
hearing,  nor 
pouch,  nor  fins, 
and  the  branchiae 
are  four  in  num- 


m      p 


Fig.  16. — NAUTILUS. 


26.  A  great  number  of  shells  are  found  in  the  fossil  state 
which  are  very  analogous  in  structure  to  the  nautilus,  and  which 
probably  belonged  to  cephalopods  of  similar  conformation ;  they 
are  the  AMMONITES  (Jig.  17),  vulgarly  called  Horns  of  Ammon, 
in  consequence  of  the  resemblance  of 
their  volutes  or  whorls  to  those  of  a 
ram's  horn.  These  animals  were 
among  the  most  ancient  inhabitants  of 
the  earth  and  lived  in  every  sea.  Their 
remains  abound  in  the  secondary  for- 
mations (See  GEOLOGY),  and  are  met 
with  in  all  parts  of  the  world  ;  but  they 
have  long  since  disappeared  from  the 
surface  of  the  earth,  and  in  those  lay- 
ers which  rest  upon  the  chalk,  not 
Fig.  17. — AMMONITE. 


quently,  their  destruction  must  have  occurred  at  a  period  long 

Explanation  of  Fig.  1  6.  —  The  nautilus  shell  opened  :  —  t.  the  tentacula  ;  — 
e.  the  funnel  or  reservoir  ;  —  p.  the  foot  ;  —  m.  part  of  the  mantle  ;  —  o.  the  eye  ; 
—  s.  the  syphon. 

26.  What  are  ammonites  ?    Where  are  they  found  ? 


32  BELEMNITES.— NUMMULITES,  &c. 

anterior  to  the  creation  of  nearly  all  the  mammals ;  they  vary 
much  in  form,  and  still  more  in  size ;  some  are  not  larger  than  a 
bean,  and  others  are  more  than  four  feet  in  diameter.  More  than 
three  hundred  species  of  them  are  known,  and  they  are  divided 
into  several  genera,  according  to  the  manner  in  which  the  shell  is 
rolled,  the  position  of  the  syphon,  the  form  of  the  partitions,  &c. 

27.  We  give  the  name  of  BELEMNITES  (from  the  Greek  belem- 
non,  a  dart)  to  other  fossils,  which  also  seem  to  have  belonged  to 
the  cephalopods,  but  which,  in  place  of  being  an  external  shell, 
must  have  been  lodged  in  the  interior  of  the  animal,  like  the  bone 
of  the  cuttle-fish.  They  are  conical  in  form,  and  are  chiefly 
composed  of  a  series  of  little  horns,  fitting  one  in  the  other  like 
boxes  in  a  nest,  traversed  by  a  syphon  and  terminated  anteriorly 
by  a  horny  plate  that  forms  a  sort  of  chamber,  in  the  interior  of 
•which  we  sometimes  find  the  remains  of  an  ink-bag,  similar  to 
the  sack  which  fulfils  the  same  purposes  in  the  naked  cephalo- 
pods. The  belemnites  are  not  met  with  in  strata  as  old  as  the 
ammonites  ;  but  they  abound  in  the  middle  and  upper  layers  of 
the  secondary  formation,  and  cease  to  exist  in  the  upper  layers 
of  the  chalk. 

Until  lately,  a  host  of  microscopic  shells  of  lenticular  form  and 
without  apparent  opening,  designated  by  authors  under  the  names 
of  NUMMULITES  (from  the  Latin  numma,  a  piece  of  money), 
CAMERINES  (from  the  Latin  camera,  chamber),  FORAMINIFERA 
(from  the  Latin  foramen,  a  hole,  and  fero,  I  bear),  &c.,  were' 
referred  to  the  order  of  cephalopods ;  these  little  bodies  abound 
to  such  an  extent  in  certain  soils,  that  they  of  themselves  exclu- 
sively constitute  chains  of  hills  and  immense  banks  of  building 
stone  ;  but  they  are  also  found  in  European  seas,  and,  on  observ- 
ing them  when  alive,  we  are  convinced  that  the  animals  to  which 
they  belong  do  not  resemble  either  the  cephalopods  or  even  the 
mollusks,  in  anything  :  they  are  beings  of  a  very  peculiar  struc- 
ture, and  seem  more  to  approximate  the  polypi. 

27.  What  are  belemnites  ?  What  are  their  characters  ?  Where  are  they 
found  ? 


CLASS  OF  GASTEROPODA.  33 


LESSON  III. 

CLASS  OF  GASTEROPODA. — General  Conformation — Classifi- 
cation. 

ORDER  OF  GASTEROPODA  PULMONEA. — Organization — Division 
into  two  families. 

FAMILY  OF  TERRESTRIAL  PULMONEA. — Limax — Vaginulus — 
Helix — Bulimus — Pupa — Chondrus — Clausilia — Achatina. 

FAMILY  OF  AQUATIC  PULMONEA. — Oncliidium — Planorbis — 
Limnceus — Physa — Auricula. 

ORDER  OF  GASTEROPODA  PECTINIBRANCHIATA. — Organization 
— Cla  ssification. 

FAMILY  OF  TROCHOIDES. —  Trochus^-  Turbo — Delphinula — 
—  Turritella —  Cyclostoma —  Valvata — Paludina —  Littorina 
— Monodon — Phasianella — Ampullaria — Janthina — Nerita. 

CLASS  OF   GASTEROPODA. 

1.  Mollusks  that  are  provided  with  a  head,  and  crawl  upon  the 
belly,  or  swim  by  means  of  a  fin  formed  of  this  part  of  the  body, 
constitute  a  very  numerous  class,  the  type  of  which  is  the  slug 
and  snail.  The  body  is  elongated,  and  terminated  anteriorly  by 
a  more  or  less  developed  head,  which  ordinarily  has  tentacula 
inserted  above  the  mouth ;  the  back  is  furnished  with  a  mantle, 
which  extends  more  or  less,  and  the  belly  is  covered  by  a 
fleshy  mass,  generally  in  form  of  a  broad  disk  (fig.  18),  and 
serves  the  animal  for  crawling  on  the  ground,  but  which  is  some- 
times very  much 
compressed,  and 
then  constitutes  a 
vertical  fin  (fig. 
78).  Many  of  these 
animals  are  en- 
tirely naked; 
others  have  an  in- 
ternal shell  con- 
cealed in  the  thick- 
ness of  the  mantle ; 
but  most  of  them 
have  an  external  Fig.  18.— LIMN*— FRESH-WATER  SNAIL. 

shell,      and      this 

calcareous  envelope  is  almost  always  sufficiently  large  to  contain 
them  entirely,  and  afford  them  protection. 

1.  What  is  the  general  character  of  the  class  of  ga'steropods  ?  Have  they 
any  shell  ? 


34 


COLUMELLA.— UMBILICUS. 


2.  The  arrangement  of  these  shells  varies  much  ;  sometimes 
they  are  composed  of  many  pieces,  at  others,  of  a  single  piece  , 
sometimes  they  are  symmetrical,  at  others  not  symmetrical,  and 
in  this  last  case,  in  proportion  as  they  are  elongated,  they  are 
rolled  or  twisted  upon  themselves,  and  constitute  a  spirally 
twisted  cone.  This  last  form,  which  is 
seen  in  the  shell  of  the  snail,  is  the  most 
common  in  gasteropods,  and  presents 
numerous  varieties.  Sometimes  the  part 
which  grows  less  rapidly  and  upon  which 
the  cone  rolls  itself,  is  full  (fig.  19),  and 
s  sometimes  empty  ;  it  is  called  columella 
or  pillar  (c),  and,  when  empty,  we  give 

d  the   mime  of  vmbilicus   to   this   opening 

(fig-  20>  M)-     ^  the   turns  of  the   shell 
^  remain   in  the   same  plane,   the  spire  is 

p.      lq  flat  or  concave,  and  the  general  form  of  the 

A  '? URB™EECDrlS0HEL°LF    she11  is  ^SCQ^  resembling  a  disk,  as  in  the 

A     i  U KlilJN  A 1  tiU     bHbJLL.  .  i'       /    /*        r»rk\  >.•  i        L     •     Lt 

planorbis  (jig-  29) ;  sometimes  the  height 

of  each  turn  completely  envelopes  thepreceding  involutions,  so  that 
the  spire  is  concealed  ;  but  in  most  cases  the  turns  are  inclined 
towards  the  edge  of  the  columella,  and  there  results  an  oblique 
spire,  which  is  more  acute  in  proportion  as 
the  cone  is  less  rapidly  widened  (fig.  19). 
Those   shells    are    called    turbinated,    in 
which  the  first  turns  are  raised  up  above 
the  succeeding  ones   (fig.  19),  forming  a 
projecting  spire,   and  it    is  remarked  that  U ... 
the  turns  or  whorls  are  almost  always  di- 
rected from  the  right  side.    Sometimes  how- 
ever the  spire  of  these  turbinated  shells  is 
turned  from   the    left   side  of  the  animal 
(fig.  25),  and  in  this  case  they  are  said  to          Fig,  20.  NATICA. 
be  perverse. 


Explanation  of  Fig.  19. — Section  of  a  turbinated  shell  to  show  how  it  is 
spirally  wound  upon  itself: — 6.  the  mouth  or  aperture  of  the  shell  ; — c.  the 
columella; — d.  the  part  of  the  columella  included  in  the  last  turn  of  the  spire  ; 
— 8.  turn  of  the  spire  next  to  the  last; — p.  the  apex  or  summit  of  the  shell ; — 
i.  part  of  the  columella. 


2.  Do  the  shells  of  ga'steropods  consist  of  a  single  piece  ?  What  is  meant 
by  the  colume'lla  ?  What  is  the  umbili'cus  ?  What  is  meant  by  a  turbinated 
shell  ?  What  is  meant  by  a  perverse  shell  ? 


STRUCTURE  OF  GASTREOPODS. 


85 


ap  p 


3.  The  mass  of  the  viscera  occupies  the  upper  part  of  the 
cone  formed  by  these  shells,  and  always  remains  enclosed  in  it  ; 
but  the  head  and  foot  project  externally  when  the  animal  extends 
itself  to  walk,  and  return  again  into  the  last  turn  of  the  spire, 
when  it  contracts  :  and  the  size  of  this  latter  part  of  the  shell  and 
the  form  of  its  open- 

ing   are    always   in 

relative  proportion  to  f 

the  Toot.     In  most  of     *' 

the  aquatic  gastero- 

pod  mollusks,  with  a     . 

spiral  shell,  there  is    l" 

a  horny  or  calcare-  P"' 

ous    disk    or    door,  o-r  —  j 

called  operculum 

(fg.  32,  o),   which 

is  fixed  to  the  poste- 

rior part  of  the  foot, 

and  which  closes  the 

entrance  of  the  shell, 

when      the     animal 

retires      into      it.- 

The  operculum  of  certain  small  shells  constitutes  what  is  vulgar- 

ly termed  an  eye-stone. 

4.  The  organs  of  respiration  are  formed  sometimes  for  breath- 
ing the  air,  and  sometimes  for  aquatic  respiration  ;  but  in  mollusks 
with  a  spiral  shell,  they  are  always  lodged  in  the  last  turn  of  the 
spire,  and  receive  the  ambient  element  beneath  its  edge,  either  by 
a  hole  pierced  through  the  mantle,  or  between  the  body  and  the 
free  edge  of  this  cutaneous  fold,  which  is  also  often  prolonged 
into  a  canal,  by  means  of  which  the  animal  can  obtain  the  fluid 
(whether   air  or    water)    necessary   for  its  respiration,    without 


0 ! 


e        d        pi 

21.  -ANATOMY  OF  A  SNA  n.. 


Explanation  of  Fig.  21. — Anatomy  of  a  snail ; — pi.  the  foot; — t.  the  tenta- 
cles partly  contracted  ; — d.  a  sort  of  diaphragm  which  separates  the  respira- 
tory cavity  from  the  other  viscera ; — e.  a  portion  of  the  stomach ;— /.  the 
liver ; — o.  the  ovary  ; — i.  the  intestines  ; — r.  the  rectum  ; — a.  the  anus  ; — c. 
the  heart  (the  pericardium — the  sack  containing1  the  heart — being  open  ; — 
ap.  the  pulmonary  artery  ramifying-  on  the  parietes  of  the  pulmonary  cavity 
(p)  ; — v.  the  gland  which  secretes  the  viscosity ; — cv.  its  excretory  canal, 
going  to  open  near  the  anus. 


3.  In  what  part  of  spiral  shells  are  the  viscera  of  the  animal  contained  ? 
What  part  of  the  shell  contains  the  head  and  foot  ?  What  is  the  operculum  ? 
What  are  eye-stones  ? 

4.  In  what  part  of  the  spiral  shells  are  the  organs  of  respiration  placed  ? 
By  what  means  is  the  air  or  water  admitted  to  these  organs  ?    Where  is  the 
respiratory  tube  situated  ? 


36  STRUCTURE  OF  GASTEROPODS. 

putting  its  head  or  foot  out  of  its  shell.  In  this  latter  case,  the 
shell  has  on  its  edge  a  notch  or  canal,  destined  to  lodge  the  re- 
spiratory tube  ;  this  notch  is  near  the  termination  of  the  columella, 
and  on  the  side  opposite  to  that  towards  which  the  spire  is  di- 
rected. Consequently  this  canal  is  to  the  left,  in  the  common 
species,  and  to  the  right,  in  perverse  shells. 

5.  The  heart  {Jig.  21,  c)  is  always  aortic  :  it  is  generally  com- 
posed of  an  auricle  and  a  ventricle,  and  its  position,  as  is  the 
case  with  the  respiratory  tube,  is  in  relation  to  the  direction  of 
the  spire  of  the  shell.     This  organ  is  situate  on  the  same  side 
with  the  tube,  that  is,  on  the  side  opposite  to  that  towards  which 
the  shell  turns,  and  the  procreative  organs  (the  form  of  which 
varies  much)  are  always  placed  on  this  latter  side,  and  conse- 
quently on  the  side  opposite  to  the  heart. 

6.  The  mouth  is  surrounded  by  contractile  lips,  and  sometimes 
armed  with  horny  teeth  which  occupy  the  palate.    In  many  other 
animals  of  this  class,  the  anterior  part  of  the  O3sophagus  is  very 
fleshy,  and  possesses  the  faculty  of  projecting  itself  externally,  in 
such  a  manner  as  to  constitute  a  trunk.     Sometimes  the  stomach 
is  also  furnished  with  cartilaginous  or  bony  pieces,  proper  for 
dividing  food;  the  intestine  is  folded  on  itself  and  lodged  between 
the  lobes  of  the  liver  arid  ovary;  and  the  anus  (fig*  21,  a)  is 
almost  always  situate  on  the  right  side  of  the  body. 

7.  In  this  class,  the  organs  of  the  senses  are  less  developed 
than  in  the  cephalopods  ;  the  tentacles,  which  most  gasteropods 
bear   on  their  front,  varying  in  number  from  two  to  six,  serve 
chiefly  for  tact  and  perhaps  for  smell.     No  organ  of  Hearing 
has  been  found,  and  their  eyes,  which  are  sometimes  wanting, 
are  very  small,  and  of  a  very  simple  structure:    they  resemble 
those  of  the  nautilus,  and  are  sometimes  adherent  to  the  head, 
and  sometimes  borne  at  the  base  on  the  side,  or  at  the  end  of  the 
tentacula. 

8.  The  class  of  gasteropods  is  divided  into  eight  orders,  the 
principal  characteristics  of  which  are  derived  from  the  disposition 
of  the  branchial  (brank-e-al]  apparatus,  as  may  be  seen  in  the 
following  table  : 


5.  What   is  the  character  of  the  heart  in  ga'steropods  ? 

6.  What  are  the  peculiarities  of  the  digestive  organs  ? 

7.  Where  are  the  tenta'cula  placed  ?    What  is  the  number  of  tentacles  in 
ga'steropods  ?    Where  are  their  eyes  situated  ? 

8.  Into  how  many  orders  is  the  class  of  ga'steropods  divided  ?  Upon  what 
are  these  divisions  founded  ? 


CLASSIFICATION  OP  GASTEROPODS. 


87 


O 


having  lungs 


(ORDERS.) 
•{  PULMONEA. 


...  I 


in  a  dorsal 
cavity,  open 
above      the 
head. 
Shell 


Tubiform,         J- TUBULIBRANCHIATA. 


Very  open ;    "j 
ordinarily  in    [ 
form  of  a 
shield. 


•8 


beneath  a  fold  of  the  mantle,  1 
which   almost    always  con-  I  TKCTIBRANCHIATA 
tains  a   shell,   or  beneath  a  f  A 
.  straight  edge  of  the  foot,        j 

{shell  not    turbi-  f 
nate;  of  one   or  >  CYCLOBRANCHIATA. 
more     pieces,    i 
Without  a  shell  }•  INFEROBRAJJCHIATA. 


{  upon  the  back. 


}•  NUDIBRANCHIATA. 


vertically  compressed,  and  only  fit  for   i  HETEROPODA. 
.swimming.  ^ 

ORDER   OF  GASTEROPODA    PUUKONEA. 

9.  Gasteropods  formed  for  aerial  respiration  have  no  branchiae, 
but  have  a  cavity  on  the  back,  upon  the  parietes  of  which  the 
pulmonary  vessels  form  a    complicated  net-work  (See  fig.  21, 
page  35),  and  the  lung  receives  the  external  air  through  a  hole 
in  the  edge  of  the  mantle  above  the  right  side  of  the  nape,  which 
is  susceptible  of  being  opened  or  shut  at  the  will  of  the  animal. 
All  the  pulmonic  gasteropods  are  not  however  terrestrial  mol- 
lusks.     Many  of  them  live  in  the  water;   but   then    they  are 
obliged  to  come  to  the  surface  from  time  to  time,  to  obtain  air 
necessary  for  their  respiration.     All  these  animals  feed  on  vege- 
table substances. 

10.  The  order  of  pulmonic  gasteropods  is  divided  into  two 
families ;  the  terrestrial  pulmonea^  and  the  aquatic  pulmonea. 

11.  The  FAMILY   OF  PULMONEA    TERRESTRIA  are  general- 
ly recognised  with  ease  by  their  four  tentacles.     These  append- 
ages  are  retractile,  and  those  forming   the  upper  pair,  which 

9.  What  are  the  general  characters  of  the  breathing  apparatus  of  the 
order  of  Ga'steropoda  Pulmonea  ?     Upon  what  do  they  feed  ? 

10.  How  is  the  order  of  pulmonic  ga'steropods  divided  ? 

11.  What  are  the  characters  of  the  family  of  terrestrial  pulmonea? 


SLUGS. 


are  longest,  have  the  eyes  at  their  extremities.  The  mouth  is 
armed  with  one  palatine  tooth,  and  a  small  tongue  studded  with 
microscopic  teeth ;  and  the  body  varies  in  form  ;  some  are 
naked  or  only  provided  with  an  internal  shell,  while  others  have 
an  external  shell  spirally  twisted,  with  a  blunt  summit,  and  the 
mouth  without  a  notch.  The  small  tribe  formed  by  the  first  is 
divided  into  Limax,  Vaginula,  &c.  The  tribe  ofterrestrialpul- 
monea  with  an  external  shell  comprises  the  genera  of  helix,  vitrina, 
bulimus,  pupa,  chondrus,  succinea,  clausilia,  and  achatina. 

12.  The  LIMACES  (slugs)  form  the  type  of  the  terrestrial 
pulmonea  without  apparent  shell.  The  body,  as  every  one 
knows,  is  elongated,  and  their  mantle  is  a  fleshy  disk,  scarcely 
separated  from  the  rest  of  the  skin  (Jig.  22,  m,)  and  which  only 
occupies  the  fore  part  of  the  back,  where  it  covers  the  pulmo- 
nary cavity ;  it  often  encloses  in  its  thickness  a  small,  flat  shell. 
On  the  right  side  of  this  species  of  shield,  there  is  a  notch,  at 
the  bottom  of  which  we  observe  a  contractile  opening  (fig.  22, 
ro),  that  leads  into  the  pulmonary  cavity  ;  the  anus  is  situate 
upon  the  anterior  border  of  this  respiratory  orifice,  and  a  third 
opening  belonging  to  the  procreative  apparatus  is  situate  on  the 
external  side  of  the  base  of  "the  right  superior  tentacle.  The 
four  tentacula  are  cylindrical,  more  or  less  swelled  at  the  end, 
and  hollow  ;  they  are  drawn  in  and  pushed  out,  on  unrolling 
themselves,  like  the  inverted  fingers  of  a  glove,  by  the  aid  of 
muscular  fibres  lodged  in  their  interior ;  the  eyes,  which  are 
borne  on  the  ends  of  the  superior  tentacles  (fig.  22,  st),  are 
black ;  the  mouth  is  armed  with  a  sort  of  palatine  tooth  in  the 
form  of  a  crescent,  and  a  smooth  tongue.  The  heart  is  lodged 
in  a  particular  cavity  beneath  the  mantle,  and  is  composed  of  an 
oval  auricle,  which  receives  a  large  pulmonary  vein,  and  a  pear- 
shaped  ventricle,  from  which  the  aorta  arises.  And  there  exists 
near  the  heart  a  secretory  apparatus  which  pours  out  a  viscid 
matter  upon  the  external  surface,  through  an  excretory  canal, 
opening  near  the  respiratory  orifice. 

13.  These  animals  are  herbivorous:  they  feed  principally 
upon  young  plants,  fruits,  mushrooms,  and  are  most  voracious 
towards  evening.  During  the  heat  of  the  day  they  remain  con- 
cealed in  holes  under  stones,  or  some  heap  of  half-decayed 
leaves,  or  even  in  the  earth,  and  they  seldom  go  out  except  in 
the  morning  and  evening,  when  the  air  is  humid ;  they  are 
especially  abundant  after  rain.  During  the  cold  season  they 
bury  themselves  in  the  ground  and  remain  torpid. 

12.  What  are  the  general  characters  of  the  Lima'ces  ? 

13.  Upon  what  do  the  Lima'ces  feed  ?     Where  are  they  found  ?     What 
becomes  of  them  in  the  cold  season  ? 


SLUGS.— SNAILS. 


14.  Some,  called  ARIONS,  have  the  pulmonary  orifice  situate 
near  the  anterior  part  of  the  dorsal  shield,  such  as  the  Limax 
rufus,  which  is  everywhere  met  with  in  wet  weather;  [a  de- 
coction of  this  species  is  sometimes  used  in  France  for  pulmo- 
nary disorders  :]  the  others,  named  Limax  properly  so  called,  or 

m          ro 

4h» 

••-.  st 


Fig.  22. — LIMAX  RUFUS. 

Lima,  have  this  orifice  situate  more  posteriorly,  and  frequently 
have  a  pretty  well  formed  internal  shell ;  the  Limax  cinereus, 
wm'ch  inhabits  caves  and  shady  forests,  belongs  to  this  division, 
as  well  as  the  Limax  agrestis,  which  abounds  in  some  countries, 
and  is  very  injurious  to  agriculture. 

We  give  the  names  of  VAGINULA,  TESTACELLA,  and  PARMA- 
CELLA  to  other  naked  gasteropods,  nearly  resembling  the  limaces, 
but  which  differ  from  them  in  the  position  of  the  anus,  the  extent 
of  the  mantle,  &c. 

15.  The  SNAILS — Helix — form  the  most  important  tribe  of 
terrestrial  pulmonea  with  a  complete  and  apparent  shell. — 
Their  organization  differs  very  little  from  that  of  the  limaces ; 
the  mantle,  instead  of  being  in  the  form  of  a  convex  shield, 
constitutes  a  large  cone  twisted  on  itself,  containing  the  viscera, 
which  is  covered  by  the  shell  (fig-  21,  p.  35).  We  distinguish 
them  by  their  shell,  the  opening  of  which  is  ordinarily  raised 
like  a  pad  or  collar,  forming  a  thickened  lip  in  the  adult ;  the  shell 
is  a  little  twisted  by  the  projection  of  the  penultimate  whorl  of 
the  spire,  and  in  this  way  takes  somewhat  of  a  crescent  shape. 
In  snails  properly  so  called,  this  opening  is  at  least  as  broad 
as  high,  and  the  shell  is  sometimes  globular  and  sometimes 
depressed.  The  habits  of  these  mollusks  are  nearly  the  same 
as  those  of  the  limaces.  In  summer  they  are  very  voracious, 
but  in  the  autumn  they  eat  very  little,  and,  on  tbe  approach  of 

Explanation  of  Fig.  22. — Limax  rufus  : — st.  the  eyes  on  the  extremity 
of  the  superior  tentacles ; — m.  the  mantle ; — ro.  the  notch  over  the  pulmona- 
ry cavity. 

14.  What  are  Arions  ? 

15.  What  are  the  general  characters  of  snails  ?  What  are  their  habits  ? 
Do  their  wounds  heal  ?    In  what  respect  does  the  genus  Heiu  differ  from 
the  genus  Limax  ? 


40 


BTJLIME8,— PUPA, 


winter,  they  retire  into  some  hole,  draw  themselves  into  their 
shell,  shutting  up  the  mouth  with  a  calcareous  matter,  secreted 
by  the  edge  of  the  mantle,  and  remain  torpid  until  spring. — 
Very  curious,  and  frequently  repeated  experiments,  have  proved 
that  not  only  do  wounds  inflicted  'on  these  animals  readily  heal, 
but  that  considerable  portions  of  the  body,  after  being  removed, 
can  be  renewed.  The  eyes,  the  tentacles,  and  even  the  head  of 
snails  have  been  known  to  be  entirely  renewed  in  this  way.  A 
very  great  number  of  species  of  snails  are  known  ;  they  are  found 
in  all  parts  of  the  world. 

16.  We  give  the  name  of  VITRINA  to  snails 
the  shell  of  which  is  very  thin,  flattened  ami  un- 
provided with  a  thickened  lip,  and  too  small  to 
enclose  the  body  entirely  f  some  small  species 
are  found  in  Europe.  The  BULIMES — Bulimus 
(Jig.  23) — have  an  elongated  shell,  the  open- 
ing higher  than  wide,  furnished  with  a  thicken- 
ed lip,  and  without  notches.  A  small  species 
which  is  found  in  France,  is"  re- 
markable for  the  singular  habit  of 
successively  breaking  the  whorls  of 
the  apex  of  the  shell.  There  is  a 
large  species  in  Brazil  which  is 
eaten  as  a  delicacy.  Other  mollusks  of  the  same 
tribe,  the  genus  Pupa,  have  an  ellipsoid,  or  even 
almost  cylindrical  shell,  with  the  opening  higher 
than  wide,  furnished  with  a  thickened,  notched,  and 
generally  dentate  lip  (Jtg.  24) :  they  are  of  small 
size,  and  live  in  humid  places,  among  moss,  &c. 
Shells  of  the  genus  Chondrus  also 
have  a  notched  and  dentate  lip;  but 
their  form  is  more  ovoid. 

17.  The  genus  of  CLAUSILIA  is  composed  of  small 
mollusks  which  live  in  moss,  at  the  roots  of  trees,  and 
have  a  shell  similar  to  that  of  the  Pupa,  but   much 
more  slender  and  pointed  (Jig'  25). 

18.  The  AMBRETTES — Succinea — differ   from  all 
the  preceding  in  the  absence  of  a  thickened  lip  around 
the  opening  of  the  shell,  which  is  oval,  and  too  -small 


Fig.  23. 

BULIMUS. 


Fig.  24. 

PUPA. 


16.  What  is  the  Vitrina?    What  are  the  characters  of  the  genus  Buli. 
mus  ?    How  is  the  gejius  Pupa  distinguished  ? 

17.  Of  what  is  the  genus  Clausi'lia  composed  ? 

18.  What  are  the  distinguishing  marks  of  the  Ambrettes  ?    Where  are 
they  found  ? 


ACHATINA.— ONCHIDIUM. 


41 


Fig.  26. 

AMBRETTE. 


to  lodge  the  entire  animal  (jig.  26) :  the  shell 
is  thin  and  translucent,  and  obtains  its  name 
from  a  supposed  resemblance  to  amber:  they 
live  upon  plants  that  grow  along  the  margins 
of  rivulets  and  brooks. 

19.  The  genus  of 
ACHATINA  (Jig. 
27)  is  composed  of 
large  snails,  which, 
in  warm  countries, 
feed  on  shrubs  ;  they  have  an  oblong 
shell  with  the  opening  wider  than  it 
is  high,  without  a  thickened  lip,  and 
truncate  at  the  extremity  of  the  colu- 
mella,  a  disposition  somewhat  analo- 
gous to  that  of  the  shell  of  most  ma- 
rine gasteropods. 

20.  The    family    of    PULMONEA 
AQUATICA    have    but    two   tentacles 
(fig.  18,  page  33);   their   mode  of 
respiration  obliges  them  to  come  fre- 
quently to  the  surface  of  the  water  to 
breathe  :    they  cannot   keep  at  great 
depths,  and    they    ordinarily  live   in 
fresh  waters,  or  near  coasts. 

21.  As  in  the  preceding  family,  we  find  here  mollusks  without 
a  shell,  and  others  that  are  provided  with  one :  the  first  form  the 
genus  of  Onchidivm  (fig.  28),  which  have  a  very  straight  and 
very  extensible  elongated  body ;  they  inhabit  the  fresh  waters  of 


Fig.  27. — ACHATINA. 


Fig.  28. — oNCHiniuM 


19.  What  shells  form  the  genus  of  Achatina?  (pronounced  a-ka-te-ncT), 

20.  What  are  the  characters  of  the  family  of  Pulmonea  Aquatica. 

21.  What  are  the  characters  of  the  genus  Onchidium  ? 


42 


PLANORBIS.— LIMN.EA PHYSA.— AURICULA. 


Fig.  29. PLANORBIS. 


the  warm  parts  of  both  continents  :  the  second  are  subdivided  into 
the  genera  of  PLANORBIS,  LIMN.EA,  AURICULA,  &c. 

22.  The  mollusks  of  the  genus  PLANORBIS  have  a  thin  shell 
rolled  upon  the  same  plane,  which  is  consequently  discoid,  and 
the  whorls  very  gradually  increase  in  size  (Jig.  29).  Their 

tentacles  are  long  and 
filiform,  and  the  eyes 
are  placed  at  the  internal 
side  of  their  base.  These 
gasteropods  feed  on  vege- 
table substances,  and  in- 
habit stagnant  waters ;  in 
winter  they  bury  them- 
selves in  the  mud,  and 
lie  torpid. 

23.  The  LIMN.EA  (fig. 
18,  page  33)  have  the 
same  habits,  and  are  almost  always  found  in  the  same  localities 
as  the  planorbis,  from  which  they  are  readily  distinguished  by 
the  form  of  their  shell,  the  spire  of  which  is  oblong ;  their  tenta- 
cles are  thick  and  triangular.  In  the  laying  season,  they  are 
often  found  in  great  numbers  joined  together,  so  as  to  form  a  sort 
of  chaplet.  They  swim  on  the  back  with  the  ventral  disk  extend- 
ed on  the  surface  of  the  water,  and  in  winter  they  become  torpid 
like  the  planorbis. 

24.  We  give  the  name  of  PHYSA 
to  small  mollusks  found  in  foun- 
tains, the  shell  of  which  (fig.  30)  is 
similar  to  that  of  the  limnsea,  but 
very  thin,  without  a  thick  lip,  and 
without  a  fold  on  the  columella. 
The  animal,  when  it  crawls  or 
swims,  covers  its  shell  with  the  two  lobes  of 
its  mantle.  In  other  respects  it  closely  re- 
sembles the  limneea. 

25.  The  AURICULAE  differ  from  the  pre- 
ceding by  having  large  oblique  grooves  upon 
the  columella  of  their  shell,  which  is  oval  or  Fig.  31. 

oblong   (fig.    31).      The   name   is   derived          AURICULA. 

22.  What  are  the  characters  of  the  genus  Planorbis  ?     Upon  what  do  ani- 
mals  of  this  genus   feed  ?     Where  are  they  found  ? 

23.  How  is  the  genus  Limnse'a  distinguished  from  the  genus  Planorbis  ? 
What  are  the  habits  of  this  genus? 

24.  What  are  the  characters  of  the  genus  Physa? 

25.  How  is  the  genus  Auri'cula  characterized  ?    (Auri'oula  ia  formed 
from  the  Latin,  aunt,  ear,  and  means  a  little  ear.) 


Fig.  30. 

PHYSA. 


STRUCTURE  OF  THE  TURBO  PICA. 


43 


from  the  shape  of  the  opening,  resembling  a  human  ear.  Many 
of  these  gasteropods  are  of  considerable  size.  One  species  is 
found  on  the  shores  of  the  Mediterranean. 

ORDER   OF   PECTXNXBRANCHXATA.* 

26.  This  division  of  the   class  of  Gasteropods   is  the    most 
numerous  in  genera  and  species  :  it  comprises   nearly  all   the 
mollusca,  in  which  the   shell  is  univalve  and  spirally  twisted, 
m  vb  b  ab  ov 


Fig.  32. — ANATOMY  OF  A  PECTINIBRANCH  GASTEROPOD.   Turbo  PlCd  (See  Jig.  44). 

Explanation  of  Fig.  32. — Anatomy  of  a  pectinibranch  gasteropod  (the 
Turbo  pica},  to  show  the  arrangement  of  the  respiratory  cavity  : — p.  the  foot 
of  the  animal ; — o.  the  operculum  ; — t.  the  trunk  ; — ta.  the  tentacles  ; — y.  the 
eyes  ; — m.  the  mantle,  split  open  longitudinally  so  as  to  expose  the  respi- 
ratory cavity  :— /.  the  anterior  edge  of  the  mantle,  which  in  its  natural  po- 
sition covers  the  back  of  the  animal,  and  leaves  there  an  opening  or  great 
slit,  through  which  the  water  reaches  the  branchiae  ; — b.  the  branchia?  : — vb. 
the  branchial  vein  which  goes  to  the  heart  (c) ; — ab.  the  branchial  artery  ; — 
a.  the  anus ; — i.  the  intestine  ; — e.  the  stomach  and  liver ; — ov.  the  oviduct. 
Above  the  nucha  or  nape,  we  see  the  cephalic  (nervous)  ganglion,  and  the 
salivary  glands  ; — d.  fringed  membrane,  which  below  borders  the  left  side 
of  the  opening  of  the  respiratory  cavity. 

*  Pec'tinibranchia'ta. — From  the  Latin,  pecten,  a  comb,  and  branchi<Bt 
gills  ;  because  the  branchiae  or  gills  (Jig.  32,  6)  resemble  a  comb  in  form. 


26.  What  are  the   peculiarities  of  the  pectinibranch  ga'steropods  ? 
what  parts  of  the  shell  do  we  find  the  respiratory  cavity  ? 


In 


44      RESPIRATORY  CAVITY  OF  PECTINIBRANCHIATA. 

and  many  of  those  in  which  the  shell  is  simply  conical.  The 
most  remarkable  feature  of  almost  all  these  animals  is  the  ar- 
rangement of  the  branchial  apparatus;  but  this  character  is  not 
constant ;  for  in  two  genera  (cyclostoma  and  helicina),  which,  in 
other  respects,  are  too  nearly  allied  to  the  ordinary  pectinibran- 
chiata  to  be  separated  from  them,  there  are  no  branchiee,  and 
their  respiration,  which  is  aerial  as  in  pulmonea,  is  carried  on 
by  means  of  a  vascular  net-work  that  lines  the  bottom  of  the 
respiratory  cavity.  This  cavity  occupies  the  last  whorl  of  the 
shell  and  opens  externally  by  a  ejreat  slit,  situate  betwixt  the  body 
and  the  edge  of  the  mantle;  in  most  instances  it  lodges  branchise 
(j%"'  *^»  ^)'  wmcn  are  composed  of  small  leaves  or  fringes  ar- 
ranged parallel  and  attached  to  its  superior  parietes  upon  one,  two, 
or  three  lines,  according  to  the  genus.  All  these  mollusks  have  two 
tentacles  (ta)  and  two  eyes,  sometimes  borne  on  particular  pedun- 
cles ;  the  mouth  is  in  the  form  of  a  tube  or  trunk  (J),  and  encloses 
a  tongue  armed  with  small  hooks  ;  the  males  have,  on  the  right 
side  of  the  neck,  an  appendage,  sometimes  very  thick,  which 
cannot,  in  general,  be  drawn  into  the  body  of  the  animal,  but  is 
folded  into  the  branchial  cavity  ;  the  rectum  and  the  oviduct  (ov) 
are  also  found  on  the  right  side  of  this  cavity,  and  near  them  we 
remark  a  particular  organ,  enclosing  a  very  viscid  humour,  de- 
signed to  form  a  common  envelope  around  the  eggs. 

27.  This  order  is  divided  into  three  families.  In  the  two 
first  (that  of  the  Trochoides  and  of  the  Capuloides),  there  is  no 
syphon  by  the  aid  of  which  the  animal  can  breathe  without 
leaving  its  shell  (Jig.  33),  while  in  the  third  family  (that  of  the 
Buccinoides)  there  is  a  respiratory  tube,  formed  by  a  prolonga- 
tion of  the  edge  of  the  pulmonary  cavity  of  the  left  side,  which 

ses  through  a  corresponding  canal  or  notch,  in  the  shell 
.34). 


Fig.  33. — TURRITELLA.  Fig.  34. — CASSIS. 


27.  How  is  the  order  of  pectinibranch  ga'steropods  divided?  How  does 
the  family  of  Buccinoides  differ  from  the  other  two  families,  the  Trochoides 
and  Capuloides  ? 


TROCHUS.  45 


28.  The  family  of  TROCHOIDES  are  distinguished  from  other 
pectinibranch  gasteropods  without  a  syphon,  by  the  form  of  their 
shell,  which  is  spiral,  with  an  entire  aperture,  and  by  the  exist- 
ence of  an  operculum,  or  some  organ  in  the  place  of  it.     This 
family  is  divided  into  three  tribes,  which  are  distinguished  by 
the  form  of  the  opening  of  the  shell ;  namely,  Trochus,  in  which 
this  opening,  angular  at  its  external  edge,  is  nearly  quadrangular, 
and,  as  regards  the  axis  of  the  shell,  lies   in   an  oblique  plane 
(Figs.  35  and  36) ;  the  tribe  Turbo,  in  which  the  mouth  of  the 
shell  is  perfectly  round  (Figs.  43,  45  and  46),  and  the  tribe  of 
Hemicyclostoma,  in  which  this  opening  is  more  or  less  in  the 
form  of  a  crescent,  as  in  the  Helices  (Figs.  26  and  27). 

29.  The  TROCHUS — so  called  from   the  general  form  of  the 
shell,  that  of  a  top;  its  spire  is  more  or  less  raised,  and  terminates 
in  a  point,  and  the  circumference  is  trenchant  or  carinate :  ani- 
mals of  this  tribe  are  mollusks  with  a  short  foot,  the  mantle  or- 
dinarily furnished  on  the  edge  with  two  or  three  pairs  of  filiform 
appendages,  the  two  eyes  being  placed  on  a  swelling  at  the  base 
of  the  tentacles,  the  mouth  armed  with  a  sort  of  spirally  rolled 
tongue,  and  the  anus  opens  on  the  right  side  of  the  respiratory 
cavity,  which  encloses  two  unequal  branchiffi.     The  operculum 
is  horny,  and  marked  by  numerous  spiral  turns.     The  tribe  of 
Trochus  is  divided  into  several  little  groups,  according  to  the  ab- 
sence or  presence  of  an  umbilicus,  and  some  other  not  very  im- 
portant characters.     Figure  35  gives  a  view  of  the  base  of  the 
Trochvs  niloticus,  showing  the  umbilicus  or  hole  in  the  base  of 


u mA 


Fig.  35.  TROCHUS  NILOTICUS.  Fig.  36. 

the  columella  (w),  while  Figure  36  is  another  view  of  the  same 
shell.     The  Solarium  is  a  trochus  in  which  the  shell  is  conical  in 


28.  What  are  the  peculiarities  of  the  family  of  Trochoides  ?  (pronounced 
tro-koi-des.)     Into  how  many  tribes  is  this  family  divided  ? 

29.  What  are  the  characters  of  the  tribe  of  Trochus  ?    (pronounced 
tro-kue.) 


46 


TROCHUS. 


form  (fg.  37),  with  a  quadrangular  aperture,  and  an  extremely 
flaring  umbilicus  (Jig,  38,  u)  ;  the  anterior  edges  of  all  the  invo- 


Fig.   39.— TROCHUS    AGGLUTINANS. 


Fig.  37.  SOLARIUM    PfiRSPECTIVUM.  Fig.  38. 

lutions  or  whorls  of  the  spire  are  marked  by  a  crenulated  cord, 

that  is,  notched  on  the  edge  (Jig.  38). 

30.  Among  the  TROCHI 
properly  so  called,  with  an 
umbilicated  shell,  we  will  men- 
tion the  Trochus  agglutinansy 
which  is  found  in  the  West 
Indies  and  Pacific.  It  has  the 
singular  faculty  of  glueing  to 
itself  movable  bodies  found  on 
the  ground  on  which  it  rests  ; 
sometimes  it  glues  stones  and 
sometimes  shells  or  pieces  of 
shells,  according  to  the  place 
where  it  is  found.  From  this 
habit  of  building  out  its  habita- 
tion from  materials  not  its  own, 
it  is  sometimes  called  the  Ma- 
son (Fig.  39). 

There  are  some  without  an 
umbilicus,  very  conical,  and 
very  tall,  that  are  marked  by 
numerous  whorls  in  the  spire, 
with  crossing  striae ;  the  ex- 
tremity of  the  columella  is 
much  twisted,  and  projects  be- 
yond the  origin  of  the  lip.  A 
specimen  of  this  variety  is  seen 
in  the  annexed  figure  of  the 
telescope  trochus  (Fig.  40). 

Fig.  40. — TROCHUS    TELESCOPIUM. 


30.  What  are  the  peculiarities  of  the  Trochus  Agglutinans  ? 


TROCHUS— TURBO. 


47 


Fig.  41. TRCCHUS  CONCAVUS. 


Fig.  42. 

TROCHUS    IRIS. 


Another  variety  is  remarka- 
ble for  a  deep  excavation  at  the 
base  of  the  columella,  resem- 
bling an  umbilicus,  and  a  pro- 
jection of  the  circumference,  as 
is  seen  in  the  figure  of  the  con- 
cave trochus  (fg.  41),  which 
inhabits  the  Indian  Seas,  and  is 
considered  rare. 

There  are 
other  species, 
without  an  umbi- 
licus, conical  with 
a  very  oblique 

base;  the  aperture  large,  slightly  angular  i  the 
columella  twisted,  and  forming  a  kind  of  tooth  at 
its  termination.  Such  is  the  rainbow  trochus 
(fg.  42),  the  nacre  of  which  is  a  beautiful  golden 
green,  with  very  brilliant  reflections  of  red. 

31.  The  tribe  of  TURBO  comprises  all  the  pecti- 
nibranch  gasteropods  which  have  a  completely  and 
regularly  turbinated  shell,  terminated  by  an  entirely  round  aper- 
ture In  it  we  range  the  turbo 
properly  so  called,  delphinula,  turri- 
tella,  scalaria,  cyclostoma,  valvata, 
&c.  (fg.  43). 

32.  The  TURBOS  properly  so 
called  are  recognised  by  their  round 
or  oval  thick  shell,  in  which  the  ap- 
erture is  completed  within  by  the 
whorl  of  the  spire  next  to  the  last. 
These  mollusks  have  two  long  ten- 
tacles, which, 
at  their  base, 
externally, 

support  the  pedunculated  eyes ;  on  the 
sides  of  the  foot  we  remark  membranous 
wings,  sometimes  simple, sometimes  fringed 
or  furnished  with  one  or  two  filaments ; 
and  their  operculum  is  sometimes  horny,  at 
others  calcareous,  or  extremely  thick. — 
Among  the  varieties  of  this  genus  is  the 
Tvrbo  Pica  (fg.  44),  which  inhabits  the 

31.  What  are  the  characters  of  the  tribe  of  Turbo  ?  (Turbo  is  a  Latin 
word,  meaning  a  whirling  or  twisting.) 

32   What  are  the  characters  of  the  Turbo  properly  so  called  ? 


Fig.  43. — TURBO. 


Fig.  44. — TURBO  PICA. 


48 


SCALARIA.— CYCLOSTOMA.— VALVATA. 


Fig.  45. — DELPHINULA. 

The  Wentletrap    or 


equatorial  regions  of  the  Atlantic  Ocean.  It  is  a  common, 
heavy  shell ;  it  has  a  horny  operculum,  and  is  remarkable  for  a 
tooth  situate  at  the  orifice  of  the  umbilicus. 

33.  The  DELPHINULA  has  a  thick  shell  like  the  last,  but  rolled 
almost  in  the  same  plane,  and  the  aperture  is   entirely  formed 
by  the  last  whorl  of  the  spire  (fig.  45): 

the  most  common  species  is  remarkable 
for  its  twisted  and  branching  spines. 

34.  The  TURRITELLA  and  Scalaria 
have  a  very  elongated  spire  :  in  the  first 
(fig.  33,  page  44),  the  mouth  or  aper- 
ture of  the  shell  is  formed   as  in  the 
Turbo,  properly  so  called,  and  in  the  last, 

it  is  similar  to  that 
of  the   Delphinula. 

Precious  Scalaria  (fig-  46)  has  the  volu- 
tions connected  by  longitudinal  ribs. 

35.  The  CYCLOSTOM^E,  which  are  dis- 
tinguished by  the  absence  of  branchiae,  and 
by  their  aerial  respiration,  also  have  a  shell 
with  a  round  mouth, 
closed  by  a  thin  circu- 
lar operculum  (fig-  47, 
o)  ;  it  is  in  form  of  an 
oval  spire,  and  finely 
striated  transversely. — 
These  animals  live  in 
woods,  under  moss  and 
Fig.  46. — SCALARIA.  stones. 

36.  Finally,  the  fresh-water  mollusks,  named  VALVATA, — in 
which  the  shell  somewhat  resembles  that  of  the  Planorbis,  but 
has  a  circular  aperture,  furnished  with  an 
operculum, — also  take  their  place  here.  One 
species,  which  inhabits  stagnant  waters  in 
France,  has  been  called  the  feather  bearer, 
from  the  manner  in  which  the  branchia,  which 
is  in  form  of  a  feather,  is  protruded  and  floats 

Fig.  48.  on  tne  surface  of  the  water  when  the  animal 

VALVATA.  wishes  to  breathe. 


—  o 


Fig.  47. 

CYCLOSTOMA. 


33.  What  are  the  characters  of  the  Delphirm'la? 

34.  What  are  the  characters  of  the  Turrite'lla  and  Scala'ria? 

35.  What  are  the  characters  of  the  Cyclo'stomae  ?  (Cyclostoma  :  from  the 
Greek,  Tcuklos,  round,  and  stoma,  mouth, — round-mouth.} 

36.  What  animals  belong  to  the  genus  Valva'ta  ?  (Valvata,  Latin,  formed 
from  valvce,  folding  doors). 


PALUDINA.— LITTORINA.— MONODON. 


49 


Fig.  49. — PALUDINA. 


37.  The  tribe  of  HEMI'CYCLO'STOMA  is  composed  of  pectini- 
branch  gasteropods,  which  resemble  snails  in  the  form  of  their 
shell,  of  which  the  whorl  next  to  the  last  presents  a  sunken  arch, 
which  gives  its  aperture  more  or  less  resemblance  to  a  crescent. 
They  form   many  genera,  among  which  we  will    mention  the 
Paludina,  Littorina,  Monodonta,  Janthina,  and  Nerita. 

38.  The  PALUDINJS  were,  for  a  long  time,  confounded  with 
the  cyclostomse,  but  the  aperture  of  their  shell  is  without  the 
rolled  lip,  and  they  are  provided  with  branchiae  for  breathing  in 

water ;  they  show  the  first  vestiges  of  the 
syphon  \v.hich  always  exists  in  the  follow- 
ing family ;  we  observe  on  each  side  of 
the  body  a  sort  of  membranous  wing,  and 
on  the  right  side  this  prolongation  curves 
into  a  small  canal,  through  which  water 
is  introduced  into  the  branchial  cavity. 
Many  species  are  found  in  fresh  waters 
in  the  United  States.  A  common  species, 
the  Palvdina  vivi'para,  so  called  because 
its  young  are  born  alive,  is  marked  by 

purplish  longitudinal  bands,  and  the  shell  is  greenish ;  it  abounds 

in  the  standing  waters  of  France. 

39.  The  LITTORINA  do  not  differ  much  from  the  Paludinse, 
except   that   they    have   a    thicker   shell, 

and  inhabit  the  sea.  The  Vigneau,  or 
Turbo  littoreusi  the  shell  of  which  is 
round,  of  a  brown  colour,  streaked  with 
black,  belongs  to  this  genus  ;  it  abounds 
on  the  coast  of  France,  where  it  is  eaten 
by  the  natives. 

40.  The  MONODONS   are  distinguished 
from  the  littorinse  by  the  presence  of  a 
blunt,  slightly  projecting  tooth  at  the  base 
of  the  columella.     The  animal  generally 
bears  on  each  side  three  or"  four  filaments, 
as  long  as  the  tentacles,  and  has  the  eyes 

supported  on  peculiar  pedicles.  A  small  species,  the  Trochus 
tesselatvs,  with  a  brown  shell,  spotted  whitish,  abounds  on  the 
coasts  of  France. 


Fig.  50. 

LITTORINA    VIGNEAU. 


37.  What  is  the  characteristic  of  the  Hemi'cyclo'stoma  ? 

38.  What  are  the  characters  of  the  genus  Paludi'na  ?  (Paludina,  formed 
from  the  Latin  palus,  a  marsh.) 

39.  What  are   the  characters  of  the  genus  Littorina  ? 

40.  What  are -the  characters  of  the  genus  Monodon? 

5 


50 


PHASIANELLA.— AMPULLARIA.— MELANIA. 


Fig.  51. 

PHASIANELLA    P1CTA. 


41.  The  PHASIANELLA  (jig.  51)  have  an 
oblong  or  pointed  shell  ;  the  aperture  is  higher 
than  it  is  wide,  and  furnished  with  a  strong 
operculum  ;  the  base  of  the  columella  is  flatten- 
ed, but  there  is  no  umbilicus.  These  animals 
inhabit  the  Indian  Ocean,  and  their  shells  are 
much  sought  after  by  collectors,  on  account  of 
the  beauty  of 
their  colours. 

42.  The 
shell  of  the 
AMPULLARIA 
(Jig.  52)  is 
round,  ventri- 
cose,  with  a 

short  spire,  as   in    most   of  the 

Helices ;  the  aperture  is  higher 

than  it  is  wide,  and  provided  with 

an  operculum ;  the  columella  is 

umbilicated.      The    Ampullarise 

inhabit   the    fresh    or    brackish 

waters  of  hot  countries.     Many 

species  are  found  in  the  United 

States. 

43.  The  shell  of  the  MELANIA  (fig.  53) 
has  the  aperture   higher  than  wide,  and  it 
enlarges   opposite   to   the  spire ;   the  colu- 
mella has  neither  plicae  (folds)  nor  umbili- 
cus ;  the  length  of  the  spire  is  very  various. 
The  animal  has  long  tentacles,  the  eyes  be- 
ing at  about  one-third  of  their  length,  on 
the  external   side.      The   Melaniae   inhabit 
fresh-water  rivers ;  a  number  of  species  is 
met  with  in  the  United  States. 

44.  The  JANTHiTfjE  (fig*  54)   resemble 
snails  in  the  general  form  of  their  shell,  but 


Fig.  52. — AMPULLARIA. 


Fig.    53. MELANIA. 


differ  considerably  from  the  different  mollusks  we  have  described 


41.  How  is  the  genus  Phasiane'lla  characterized  ?     (Phasianella,  from 
the  Greek,  Phasianos,  a  pheasant,  because   this  shell  bears  some  resem- 
blance to  the  pheasant  in  its  colours.) 

42.  How  is  the  genus  Ampulla'ria  recognised  ? 

43.  What  are  the  characters  of  the  genus  Mela'nia  ?     (Melania,  from  the 
Greek,  melas,  black.) 

44.  What  are  the  characters  of  the  genus  Janthi'na  ?  (Janthina,  from  the 
<5re<?k  ianthon,  violet  colour.) 


JANTHlftA.— NERITA.  51 

in  the  form  of  the  animal.  It  has  no  oper- 
culum,  but  carries  on  its  foot  a  substantial 
vesicular  organ,  which  resembles  froth  bub- 
bles, which  hinders  it  from  crawling,  but  en- 
ables it  to  float  on  the  surface  of  the  water. 
Its  head  is  in  the  form  of  a  trunk,  and  has  a 
forked  tentacle  on  each  side.  The  common  FiZ'  ^.-J 
species — Janthinafragilis — with  a  very  thin  violet-coloured  shell, 
is  very  common  in  the  Mediterranean,  and  the  seas  of  all  warm 
regions.  Great  numbers  of  them  are  frequently  met  with  in  per- 
fectly calm  weather  floating  on  the  surface  of  the  ocean.  When 
the  animal  is  touched,  it  ejects  a  deep  violet-coloured  liquor,  which 
dyes  the  water  all  round  it.  The  vesicular  or  froth-like  buoy  is 
about  three  times  the  size  of  the  animal ;  it  is  in  the  form  of  a 
cone,  projecting  from  one  side. 

45.  The  NERIT^E  are  distinguished  by 
the  columella  being  a  straight  line,  which 
makes  the   aperture  of  the   shell   either 
semi-circular    or   semi-elliptical.      They 
are  divided  into  Natica^  in  which  the  shell 
is  umbilicate  (fig.  20,  page  34)    and  the 
operculum  horny ;  into  Nerita,  properly 
so  called,  in  which  the  shell  is  not  umbili- 
cate, thick  ( fig.  55),  and  the  operculum  Fi%'  55' 
stony,  and   into   Neritina,  in  which  the         N**'™  PELORONTA' 
shell  is  also  without  an  umbilicus,  very  *'"*  j 
thin,  and  the  operculum  is  horny.     The  last  live  in  fresh  waters. 

45.  How  is  the  genus  Neri'ta  distinguished  ? 


FAMILY  OF  BUCCINOIDES. 


LESSON  IV. 

FAMILY  OF  BUCCINOIDES. — Buccinum — Buccinum  properly  so 

called  —  Harpa  — Purpvra  — Cassis — Cerithium — Murex — 

Strombus — Voluta — Ovula — Cypr&a — Convs. 
FAMILY    OF    PECTINIBRANCHIATA    CAPULOIDA.  —  Pileopsis  — 

Hypponyx —  Crepidula  —  Calyptraa  —  Siphonaria  —  Siga- 

retus. 

ORDER  OF  GASTEROPODA  TUBULIBRAWCHIATA. 
ORDER  OF  GASTEROPODA  SCUTIBRANGHIATA. — Haliotis — Fis- 

surella — Emarginula . 
ORDER     OF     GASTEROPODA     CYCLOBRANCHIATA.  —  Patella— ~ 

Chiton. 

ORDER  OF  GASTEROPODA  INFEROBRANCHIATA. 
ORDER    OF     GASTEROPODA    TECTIBRANCHIATA. — Pleurobran* 

chus — Aplysia — Dolabella — Bullea — Bvlla. 
ORDER     OF     GASTEROPODA     NUDIBRANCHIATA.  —  Eolidia  — 

Glaucus. 

ORDER  OF  GASTEROPODA  HETEROPODA. — Carinaria. 
CLASS  OF  MOLLUSCA  PTEROPODA.  —  Clio  borealis. 

1.  In  the  FAMILY  OF  BUCCINOIDES,  the  shell  is  spiral,  and  in 
its  aperture,  near  the  extremity  of  the  cohimella,  there  is  a  canai 
or  notch,  serving  for  the  passage  of  the  syphon  or  respiratory 
tube  (fg.  56),  which  is  formed  by  a  fold  of  the  mantle,  ana 
destined  to  afford  the  animal  the  power  of  breathing,  without 
going  out  of  its  shell.     This  family  is  divided  into  three  tribes, 
namely  :  Buccinum,  Murex,  and  Angiostoma. 

2.  The  TRIBE  OF  BUCCINUM  comprises  all  the  Buccinoides  in 

which  the  shell  is  with- 
out a  plica  (fold)  in  its 
columella,  but  is  fur- 
nished with  a  notch  or 
short  canal  inflected 
towards  the  left,  and  its 
aperture  is  very  large. 
The  foot  of  these  mol- 
lusks  is  generally  of 
Fig.  56.-voLUTA.  moderate  length,  and 

rounded  in  front  (jigs.  33  and  34.)     The  mantle  is  unprovided 
with  fringe,  and  is  prolonged  anteriorly  into  a  long  canal,  which 

1.  What  are  the  characters  of  the  shell  in  the  family  of  Buccinoides  ? 
Into  how  many  tribes  is  this  family  divided  ? 

2.  How  is  the  tribe  of  Buc'cinura  characterized  ?     (Buccinum,  Latin»  a 
trumpet) 


BUCCINUM.— NASSA.— HARPA. 


53 


is  always  uncovered.     The  mouth  is  armed  with  a  trunk,  and 
there  is  generally  a  small  horny  operculum. 

3.  The  BUCCINUM  PROPERLY  so  CALLED 
(jig.  57),  has  an  oval,  elongated  shell,  the 
aperture  of  which  is  oval,  notched,  and  with- 
out a  canal.  The  operculum  is  complete,  and 
these  animals  have  no  veil  on  the  head  like 
the  Cerita.  A  great  many  species  are  known. 
Lamarck  describes  fifty-eight  species. 

4.  We    give    the   name    of 

NASSA  to  mollusks  that   differ 

very  little  from  the  preceding, 

but  in  which  the  columella  of 

the    shell,    in    place   of    being 

convex  and  naked,  is  covered  by     BUCCINUM  UNDATUM. 

a  plate  of  greater  or  less  thickness  (Jig.  58).  Dolium 

also  belongs  to  this  tribe,  arid  is 

remarkable  for  the  length  of  its 

trunk  and  the  size  of  its  foot. 

It  is  without  operculum,  and 

the  shell  is  recognised  by  being 
almost  globose,  very  ventricose  and  fur- 
nished with  projecting  ribs,  which  follow 
the  direction  of  the  whorls  of  the  spire, 
and  make  the  margin  of  the  aperture  un- 
dulated (Jig-  59).  A  very  large  species  is 
found  in  the  Mediterranean.  Fig.  59.—  DOLIUM 


Fig.  57. 


Fig.  58. 

NASSA. 


b 

Fig.  60.— HARPA. 


5.  The  HARPS—  Harpa— 

have  a  more  oval  shell, 
furnished  with  projecting  ribs 
parallel  with  the  margin  of 
the  aperture,  and  differ  from 
the  preceding  in  the  form  of 
their  foot  (fig.  60). 

6.  The   PURPURA  is    fur- 
nished  with   an   operculum, 
like  the  Buccinum  properly  so 


Explanation  of  Fig.  60. — Harp : — a.  the  shell ; — 6.  the  foot  of  the  animal ; 
— c.  the  tentacles ; — d.  the  syphon. 

3.  What  are  the  characters  of  the  Buccinum  properly  so  called  ? 

4.  What  are  the  characters  of  the  genus  Nassa?  (Nassa,  Latin,  a  net). 
What  are  the  characters  of  Do'lium  ?  (Dolium,  Latin,  tub,  a  tun). 

5.  How  is  the  Harp  characterized  ? 

6.  What  are  the  characters  of  the  genus  Pir'pura  ?  (Purpura,  Latin, 
purple.) 

5* 


54 


CASSIS.— TEREBRA.— CERITHIUM. 


called,  which  it  very  much  resembles.  The  shell  is  ovate,  thick, 
most  frequently  tuberculated,  and  characterized  by  its  flattened 
columella,  which  is  trenchant  towards  the  end  opposite  to  the 
spire,  and  forming,  at  that  point  with  the  external  margin  of  the 
aperture,  an  unprojectmg  canal. 


CASSIS. 


Fig-.  62. 


Fig.  61. 

7.  The  HELMET  — CASSIS  (figs.  34,  61,  62)  — also  very 
much  resembles  the  ordinary  Buccinum ;  but  their  shell,  which 
is  ovate,  with  a  short,  slightfy  projecting  spire,  is  furnished  with 
a  transversely  wrinkled  plate,  covering  the 
columella,  like  the  Nassa.  The  aperture, 
sometimes  oblong,  sometimes  straight,  is 
also  wrinkled  externally,  and  its  notch  termi- 
nates in  a  little  short  canal  which  is  curved 
backwards. 

6.  The  TEREBRA  differs  still  less  from  the 
Buccinum  properly  so  called  :  it  is  distin- 
guished from  it  only  by  the  elongation  of  its 
spire. 

9.  The  CERITHIUM  (fig.  63),  the  shell  of 
which  is  turreted,  like  that  of  the  Terebra,  but 
furnished  with  a  short  canal  curved  to  the  left 
or  backwards,  also  differs  from  other  Buccina 
by  having  a  veil  above  the  head  :  this  animal 
has  but  a  single  branchia.  Some  of  the  mol- 
lusks  of  this  genus  inhabit  the  sea,  and  others 
Fig.  63.  fresn  water-  A  great  manY  living  species  are 

CERITHIUM  ALUCO.        known ;  but  they  were  formerly  more  abun- 


7.  What  are  the  characters  of  the  genus  Cassis?    (Cassis,  Latin,  a 
helmet.) 

8.  How  is  Terebra  distinguished  from  Buc'cinura  ?    (Buccinum,  Latin, 
a  trumpet,  a  shell- fish.) 

9.  What  are  the  characters  of  Cerithium  ? 


MUREX.— FUSUS.— STROMBUS. 


55 


dant  than  in  our  day ;  for,  in  certain  formations,  such  as  the 
calcareous  tertiary  of  the  environs  of  Paris,  an  immense  number 
is  found  in  the  fossil  state. 

10.  In  the  TRIBE  OF  MUREX,  the  aperture  of  the  shell  is 
always  prolonged  into  a  canal,  either  straight  or  inflected 
(Jig.  64).  The  animals  themselves  very  closely  resemble 
those  of  the  tribe  of  Buccinum ;  they  have  a  trunk,  no  veU. 
on  the  head,  the  right  edge  of 
the  mantle  furnished  with  lobes  or 
filaments,  and  a  horny  operculum. 
They  are  all  carnivorous  and  inhabit 
the  sea.  They  are  subdivided,  ac- 
cording to  the  form  of  the  shell, 
into  Murex  properly  so  called, 
Fvsus,  Strombus,  &c. 

11..  The  Mu  rices  properly  so 
called  are  distinguished  by  their  shell, 
the  canal  of  which  is  projecting  and 
straight,  and  the  whorls  are  furnish- 
ed with  transverse  elevations,  in 
form  of  varices  or  ridges,  which 
often  present  spines,  or  ramified  and 
slashed  plates,  or  lamellae. 

12.  The  Fusus  has  a  canal 
formed  like  the  common  Murex; 
but  the  shell  is  without  varices,  that 
is,  longitudinal  ribs. 

Fig.  64. — MUREX. 

13,  The  STROMBUS  has  a  shell  in  which  the 
canal  is  straight  or  curved  to  the  right,  and  its 
external  edge  expands  with  age,  and  this  canal 
presents  a  sinus  (hollow)  behind,  in  which 
the  head  lodges,  when  the  animal  extends 
itself.  In  the  STROMBUS  PROPERLY  so 
CALLED,  the  sort  of  wing  formed  by  this  prolon- 
gation of  the  margin  of  the  shell  is  entire  (Jig. 
65),  while,  in  the  PTEROCERA,  it  is  divided,  in 
the  adult,  into  long  and  slender  digitations. 


Fig.  65. 

STROMBUS, 


10.  How  is  the  tribe  of  Mu'rex  characterised  ?  (Murex,  Latin,  a  shellfish.) 

11.  How  are  Mu'rices  properly  so  called  distinguished  ? 

12.  What  are  the  characters  of  Fusus  ?  (Fusus,  Latin,  a  spindle.) 

13.  What  are  the  distinguishing  characters  of  Strom/bus?   (Strombus, 
Latin,  name  of  a  shellfish.) 


56 


VOLUTA.— OLIVA.— OVULA. 


All  have  the  aperture  of  the  shell  very  narrow  (Jig. 

66),  a  disposition  approaching  to  the  characteristic  of 

the  following  tribe. 

14.  In  the  TRIBE  OF  ANGIOSTOMA,  the  aperture 

is  generally  so  narrow  that,  to  enter  it,  the  foot  of  the 

animal  is  obliged  to  be  doubled. 

In  some,  designated  under  the  com- 
mon name  of  VOLUTES — Valuta — the 
aperture,  which  is  of  various  forms,  is 
terminated  by  a  notch  without  a  canal, 
and  thecolumella  is  marked  by  oblique, 
projecting  plicee  (folds),  (fg.  67) :  they  are  sub- 
divided into  VOLUTES  PROPER  (fg>  56,  page  52), 
in  which  the  aperture  is  wide,  and  the  columella 
is  marked  by  some  large  plica?,  and  the  last 
whorl  of  the  spire  is  sometimes  ventricose,  some- 
times conical ;  in  the  MITRA  the  spire  is  in 
general  pointed  and  elongated,  and  in  OLIVA,  so 
called  from  the  oblong  or  ellipsoid  form  of  the 
shell,  the  aperture  is  long,  narrow,  and  notched 
opposite  to  the  spire,  and  the  columeila  is  marked 
by  numerous  plica?  (fig-  67). 

16.  In  others  the  shell  is  oval,  the  spire  is 
concealed,  and  the  aperture,  which  is  long  and 
narrow,  has  no  plicce  on  the  side  of  the  columella, 

but  presents  a  notch  or  canal  at  its  two  extremities  j  these  are 

the  OVUL^E  (fg.  68). 


Fig.  67. 

OLIVA. 


Fig.  68. — OVULA  VOLVA. 

17.  In  others  again,    the  CYPRJE.E  (PORCELANA),  the  shell, 
which  is  protuberant  in  the  middle,  and  almost  as  much  con- 

14.  What  is  the  peculiarity  of  the  tribe  of  Angio'stoma  ?    (Angiostoma, 
Greek,  apgeion,  a  vessel,  and  stoma,  mouth.) 

15.  What   are  the  characters  of  Volu'ta  ?     (Voluta,  Latin,  a  wreath.) 
What  is  the  character  of  Oli'va  ?    (Oliva,  Latin,  an  olive.) 

16.  What  are  the  characters  of  the  genus  O'vula?     (Ovula,  from  the 
Latin,  owwm,  an  egg.) 

17.  What  are  the  characters  of  the  genus  Cyprae'a  ?  (Cypreea,  Latin, 
a  cowry. 


CYPR^A.— CONUS. 


57 


tracted  at  the  two  extremities,  has  a  very  narrow  aperture,  trans- 
versely wrinkled  on  both  sides ;  when  the  animal  expands  it- 
self, the  mantle  extends  over  the  shell  and  envelopes  it  entirely 

(fig.  69),  which,  in  the 
progress  of  time,  pro- 
duces considerable  mo- 
dification in  the  colours 
of  the  latter ;  for,  at  a 
certain  period,  it  depo- 
sits new  layers  of  calca- 
reous matter,  not  only 

Fig,  GQ.-CYPR^A.  around  the  aperture,  but 

also  upon  the  whole  external  surface  of  this  solid  envelope. 

18.  Also  to  this  tribe  of  mollusks    belongs  the 
genus  CONUS  (fig.  70),  which  differs  from  all  the 
preceding  in    the  conical  form  of  the  shell,  which 
gives  the  genus  its  name ;  a  slightly,  or  not  at  all 
projecting  spire,  forms  the  base  of  this  cone,  and  the 
aperture,  which  is  nearly  straight,  extends  from  one 
end  of  the  shell  to  the  other. 

19.  A  great  number  of  the  shells,  the  principal 
characters  of  which  we  have  briefly  noted,  are  re- 
markable for  the  elegance  of  their  form  and   the 
beauty  of  their  colours;  the  Cones,  the  porcelain 
shells  (CypraBa),  the  Volutes,  and  the  Olives  especial- 
ly, are  much  admired  for  the  brilliance  of  their  mark- 
ings.    Many  other  mollusks  of  the  family  of  Buccinoides  are  also 
worthy  of  attention  on  account  of  the  viscid  liquid,  secreted  by 
the  gland  placed,  as  we  have  already  seen  in  the  snails,  betwixt 
the  heart  and  rectum.     And  in  a  considerable  number  of  these 
animals,  this  humour  has  the  property  of  changing  colour  when 
exposed  to  the  action  of  air  and  light,  and  thus  passes  from 
greenish  yellow  to  purple ;  spread  upon  stuffs,  it  imparts  to  them 
this  rich  shade,  and  appears  to  be  the  material  employed  by  the 
ancients  for  producing  their  beautiful  purple  dyes.     Pliny  relates 
that  on  the  shores  of  Tyre,  and  many  other  points  along  the 
coasts  of  the  Mediterranean,  there  are  found  two  genera  of  shells, 
called  Buccinum  and  Purpura,  both  of  which  furnished  dye  for 
the  colours  termed  purple  and  conchilian.     The  first  of  these 
mollusks  appears  to  be  the  Buccinum  lapillus,  and   the  second 
the  Murex  brandaris  (fig.  64) ;  but  the  quantity  of  colouring 


Fig.  70. 


1 8.  What  are  the  characters  of  the  genus  Co'nus  ?      (Conus,  Latin,  a 
cone.) 

19.  What  animals  are  supposed  to  yield  the  purple  dye  which  was  cele- 
brated among  the  ancients  ?  . 


58 


CAPULUS.— HIPPONYX.— CREPIDULA. 


matter  these  animals  yield  is  so  small,  it  is  difficult  to  explain 
how  they  could  furnish  so  active  a  trade ;  and  it  must  have  been 
that  the  ancients  used  for  the  same  purposes  the  purple  liquid 
secreted  by  larger  and  more  common  mollusks,  such  as  the 
aplysi<E)  which  we  have  yet  to  mention. 

20.  The  FAMILY  OF  PECTINIERANCH  CAPULOIDES  is  recog- 
nised by  the  shell  being  widely  open,  slightly  turbinated,  and 
without  either  notch,  syphon,  or  operculum.  The  conformation 
of  the  animal  differs  but  little  from  that  of  other  mollusks  of  the 
same  order  ;  there  is  only  a  single  branchia,  often  with  very  long 
filaments,  attached  transversely -to  the  arch  of  the  respiratory 
cavity. 

In  this  division  are  arranged  the  genera  of  Pileopsis,  Hippo- 
nyx,  Crepidula,  CalyptrcRd^  Sigaretus,  <fyc. 

21.  Animals  of  the  genus  Pileopsis,  or  Capulus 
(fig'  ^1)5  have  their  branchise  on  the  anterior  edge 
of  the  respiratory  cavity  ;  the  shell  is  conical,  and 
presents  at  its  summit  the  commencement  of  a  spire; 
their  neck  is  covered  by  a  membranous  plaited  veil, 
and  they  have  two  conical  tentacles,  and  a  tolerably 
long  trunk  or  proboscis.     They  inhabit   the  sea- 
shores of  warm  countries. 

22.  The     genus    of 
Hipponyx  (fig>  72)  con- 
sists    of     fossil     shells, 

which  closely  resemble  the  preceding, 

but  are  very  remarkable  for  a  support 

formed    by   calcareous    layers,    upon 

which  they  rest,  and  which   seem  to 

have  been  secreted  by  the  foot  of  the 

animal. 

23.  The  CrepididtJB  have  an  oval 
shell,  the  whole  base  of  which  is 
half  closed  by  a  horizontal  plate, 
which  supports  the  abdominal  sac 
above  it,  and  is  covered  beneath  by 
the  foot  (fig.  73). 
Fig.  73. — CREPIDULA. 

20.  How   is   the   family   of   Pectinibranch    Capuloi'des    distinguished  ? 
(Capuloides,  from  the  Latin,  capulus,  a  hilt  or  handle,  and  the  Greek,  eidos, 
resemblance.) 

21.  What  are  the  characters  of  the  genus  Ca'pulus?     (Capulus,  Latin,  a 
hilt.) 

22.  What  are  the  characters  of  the  genus  Hippony'x  ?     (Hipponyx,  from 
the  Greek,  ippos,  a  horse,  and  onux,  nail ;  horse  nail,  or  hoof.) 

23.  What  are  the  characters  of  the  genus  Crepi'dula  ?    (Crepidula,  Latin, 
£  slipper.) 


72-HIPPONYX- 


CALYPTR^.— SIPHONARIA.— SIGARETUS. 


59 


Fig.  74. 

CALYPTR^EA. 


24.  The  Calyptrwce  have  in  the  interior  of  the 
shell,  in  form  of  a  hollow  cone,  a  small  plate  pro- 
jecting downwards,  which  seems  to  be  the  com- 
mencement of  a  columella,  and  is  embraced  in  a 
fold  of  the   abdominal  sac ;  their  branchiae  are 
composed  of  long  slender  filaments  like  hairs. — 
In  some  of  them  the  plate  or  lamina  adheres  to 
the  bottom  of  the  cone,  being  itself  bent  into  a 
portion  of  a  cone  or  of  a  tube,  and  descending 
vertically. 

25.  The  Siphonaria  deserve  notice,  because 

they  show  how  much  the  organization  of  mollusks  may  vary  with- 
out any  very  striking  difference  in  the  form  of  their  shell.  Until 
recently  these  animals  have  been  ranged  with  the  patella3,  to  be 
described  in  the  sequel,  which  they  resemble  in  their  shell,  but 
differ  from  them  very  much  in  the  structure  of  their  most  im» 
portant  organs ;  their  branchia  is  composed  of  a  few  leaflets 
transversely  attached  to  the  bottom  of  a  respiratory  cavity, 
which  is  on  the  back,  and  communicat- 
ing externally  by  a  lateral  hole  in  the 
mantle;  they  do  not  appear  to  possess 
tentacles,  but  have  a  narrow  veil  on  the 
head. 

26.  The  genus  Sigaretus  (fg.  75) 
has  a  flattened  shell,  with  a  slight  spire, 
arid    a  very   large   aperture,   which   is 
Fig.  75.— SIGARETUS.        concealed  in  the  mantle. 


ORDER   OF  GASTEROPODA   TTJETJLIBRANCHIATA- 

27.  Tubulibranch  gasteropods  are  very  analogous  to  the 
pectinibranch  gasteropods,  but  are  distinguished  from  them  by 
very  important  differences  in  the  organization  of  some  of  their 
organs,  and  in  the  structure  of  their  shell,  which  is  fixed  to  sub- 
marine bodies,  and  is  in  the  form  of  a  more  or  less  irregular  tube, 
the  commencement  of  which  only  is  spiral.  It  is  divided  into  the 
genera  Vermetus,  Magilus,  and  Siliquaria. 


24.  What  are   the  characters  of  the  genus   Calyptrse'a?     (Calyptrse'a, 
from  the  Greek,  kaluptra,  a  hood.) 

25.  What  are  the  characters  of  the  genus  Siphona'ria  ? 

26.  What  are  the  characters  of  the  genus  Sigare'tus  ? 

27.  How   are  the   tubu'libranch   distinguished  from   the  pecti'nibranch 
gasteropods^?     (Tubu'libranch,  from  the  Latin,  tubulus,  a  little  tube,  and 
branchiae,  gills). 


60 


HALIOTIS.— FISSURELLA. 


ORDER  OF   GASTEROPODA  SCUTIBHANCHIATA. 

28.  In  the  general  form  of  their  body  and  the  position  of 
their   branchice,    the    scutibranch    resemble    the    pectinibranch 
gasteropods  ;  but  they  differ  from  the  latter  in  their  anatomical 
and  physiological  characters.     Their  shell  is  very  open,  slightly 
or  not  at  all  turbinated,  and,  like  a  shield,  it  covers  the  branchiae 
or  even  the  whole  body.     A  peculiarity  of  their  internal  organi- 
zation approximates  them  to  the  acephalous  mollusks ;  their  heart 
is  traversed  by  the  rectum  and  receives  the  blood  by  two  auricles. 
They  aro  not   numerous,  and  are   divided  into  Haliotis,  Fis- 
surella^  fyc. 

29.  The  Haliotides  (fig.  76)  have  a  slightly  turbinated  shell, 
with  a  spire  so  small  that  it  is  only  seen  from  the  inside :  it  is 
flattened    and    the   aperture  is  very  large.     In   the  Haliotides 
properly  so  called,  there  is  along  the  columella  a  series  of  holes, 

through  which  the  water  reaches 
a  slit  on  the  right  side  of  the 
mantle,  and  penetrates  to  the 
branchial  cavity  ;  the  filiform  ap- 
pendages of  the  edge  of  the  mantle 
can  be  protruded  through  these 
holes, and  all  around  the  foot  there 


Fig.  76. — HALIOTIS. 


is    a  double   membrane   cut    in 


fringes  and  furnished  with  long  filaments.  On  the  outside  of  the 
tentacles  we  find  two  cylindrical  pedicles,  bearing  the  eyes ;  and 
the  mouth  is  armed  with  a  trunk  or  proboscis.  The  external 
surface  of  the  shells  of  these  mollusks  are  not  remarkable  ;  but 
internally  they  are  covered  by  a  layer  of  nacre,  of  the  richest  and 
most  beautifully  iridescent  colours.  They  are  found  in  great  num- 
bers on  the  rocky  shores  of  California.  o 
30.  The  Fissurella,  \. 

(fig-    77)    are    rec.°g- 
nised    by  their   conical 
shell    placed    upon   the  m 
middle  of  the  back,  and  p 
pierced   at    its    summit 
by    a    small    opening 


which    serves    to    give 


Fig.  77. FISSURELLA. 


Explanation  of  Fig.  77. — p.  the  foot  of  the  animal ; — m.  the  mantle  ; — 0. 
the  opening  at  the  apex  of  the  shell,  and  the  anus. 

28.  What  are  the  characters  of  the  scuti'branch  ga'steropods  ?     (Scuti- 
branch, from  the  Latin,  scutum,  a  shield,  and  branchiae,  gills.) 

29.  What  are  the  characters  of  the  Halio'tides  ?     (Haliotides,  from  the 
Greek,  als,  the  sea,  and  ous,  ear  ;  sea-ear,  or  haliotis,  and  eidos,  resemblance.) 

30.  How  is  the   genus  Fissure'lla  recognised  ?  XFissurella,  Latin,  Fis- 
•ura,  a  slit.) 


EMARGINULA.— PATELLA. 


61 


passage  to  the  air  necessary  for  respiration,  and  also  for  the  ex- 
pulsion of  the  excrements. 

31.  We  give  the  name  of  Emarginula  to  mollusks  very  much 
like  the  Fissurellse,  but  their  shell,  m1  place  of  being  open  at  the 
top,  presents  a  slit  or  notch  in  front,  communicating  with  the 
branchial  cavity. 

ORDER  OF  GASTEROPODA  CYCLOERAI'TCHIATA. 

32.  The  cyclobranch  gasteropods  closely  approximate  the  pre- 
ceding, either  in  their  general  form,  or  in  the  disposition  of  their 
internal  organs ;  but  they  are  distinguished   by  their  branchiae 
being  fixed  around  the  edges  of  the  mantle  (Jig.  78). 

38.  Some,  the  Patella 
(fg.  78),  for  example,  are 
provided  with  a  broad-based, 
conical  shell,  which  covers 
the  whole  body  ;  they  very 
much  resemble  the  Fissurel- 
lae  and  Emarginulse,  but  the 
shell  is  not  perforated  at  the 
apex,  nor  is  there  a  notch  in  j  i 
front  as  in  the  latter.  The 
head  is  furnished  with  two 
pointed  tentacles,  having  the 
eyes  at  their  base,  and  a 
stout  trunk ;  the  anus  is 
situate  to  the  right,  and  a 
little  above  the  head,  and  the 
branchiae  are  composed  of 


Fig.  78. — PATELLA. 


leaflets  or  fringes,  arranged  in  a  row  around  the  body,  under  the 
edges  of  the  mantle.  Patellse  are  found  in  almost  all  parts  of  the 
world  ;  they  are  found  on  rocks  to  which  they  adhere,  and  lie 
completely  concealed  beneath  their  shell,  even  after  they  are  left 
by  the  ebbing  sea. 


Explanation  of  Fiy.  78.— The  animal  of  the  patella  seen  from  below  ;—e. 
the  edge  of  the  shell ; — p.  the  foot ; — m.  the  mantle  ; — b.  the  branchiee  ; — t. 
the  "head. 


31.  How  does  the  genus  Emargi'nula  differ  from  Fissure'lla?     (Emargi- 
nula, from   the  Latin,  e,  from,  and   margo,  marginis,  the   margin — from 
the  margin — notched.) 

32.  How  are    cy'clobranch   ga'steropods   distinguished  ?     (Cyclobranch, 
from  the  Greek,  kuklos,  a  wheel,  and  bragchia,  gills.) 

33.  What  are  the  characters  of  the  genus  Pate'lla?     (Patella,   Latin, 
knee-pan. 

6 


CHITON. 


34.  Other  cyclobranch  gastero- 
pods,  called  Chiton  (fig.  79),  differ 
from  all  mollusks,  in  the  nature  of 
«their  shell,  which,  instead  of  a  tur- 
binated  or  shield-like  piece,  is  com- 
posed of  a  row  of  testaceous  and 
symmetrical  scales,  generally  eight 
in  number,  let  into  the  mantle,  and 
occupying  the  middle  line  of  the 
back.  The  edges  of  this  mantle, 
thus  protected,  are  also  very 
leathery,  and  often  furnished  with 
little  scales,  spines,  or  hairs.  A 
membranous  veil  placed  over  the 
mouth,  takes  the  place  of  tentacles ; 
the  branchiae  are  composed  of 
Fig.  79.— CHITON.  lamellar  pyramids,  arranged  on  each 

side,  beneath  the  edge  of  the  mantle  ;  the  anus  is  at  the  posterior 
extremity  of  the  body.  Chitons  most  abound  on  the  shores  of 
tropical  seas. 

ORDER   OF   GASTEROPODA  INFEROBRASSTCHIATA. 

35.  The  order  of  Inferobranch  gasteropods  is  composed  of  a 
very  small  number  of  naked  mollusks,  characterized  by  their 
branchia3,  consisting  of  a  long  series  of  leaflets,  placed  on  each 
side  of  the  body,  between  the  foot,  and  the  advanced  edge  of  the 
mantle.     Like  the  preceding,  they  are  marine,  and  differ  from 
them,  not  only  in  the  absence  of  every  vestige  of  shell,  but  also 
in    some  points  of  their  internal  anatomy,  which    approximate 
them  to   the    gasteropods.     They  are   divided    into  PHYLLIDIA 
(from  the  Greek,  phullon,  a  leaf),  in  which  the  anus  is  posterior 
to   the   mantle,  and  the  head  is  furnished  with  four  tentacles  ; 
and  into  DIPHYLLIDIA  (from  the  Greek,  dis,  two,  and  phullon^ 
leaf),  in  which  the  anus  is  on  the  right  side,  and  the  head  has  a 
pointed  tentacle,  and  small  tubercle  on  each  side.     In  all  of  them, 
the  body  is  oval,  or  more  or  less  tuberculous. 

ORDER   OF   GASTEROPODA   TECTXBHANCHIATA. 

36.  The  Tectibranch  gasteropods  are,  like  the  preceding,  ma- 
rine  mollusks,  but  their  branchiae  are  not  symmetrical ;   they 

34.  What  are  the  characters  of  the  genus  Chi'ton  ?  (pronounced  Icy-ton.) 
(Chiton;  Greek,  a  garment.) 

35.  How  are  the   In'ferobranch   ga'steropods  characterized  ?     (Infero- 
branch ;  from  the  Latin,  inferus,  below,  and  branchiae,  gills.) 

36.  What  are  the  characters  of  the  tecMlbranch  gasteropods  ?     (Tecti- 
branch ;  from  the  Latin  tego,  I  cover,  and  bronchia,  gills.) 


PLEUROBRANCHUS.— APLYSIA. 


— t 


.  SO.-PLEUROBRANCHUS. 


are  composed  of  leaflets, 
more  or  less  divided,  at- 
tached along  the  right  side 
(fig.  80,  br),  or  on  the 
back  (fig.  81),  and  more 
or  less  covered  by  the 
mantle,  which  almost  al- 
ways encloses  a  small 
shell  in  its  thickness. — 
Their  form  is  very  variable.  They  are  divided  into  Pleurobran- 
chus,  Pleurobranchides,  Aplysia,  Dolabella,  Akera,  &c. 

37.  The   PLEUROBRANCHI    are    mol- 
lusks   of  an    oval    form ;   in   which    the 

t  branchiae  are  fixed  on  the  right  side, 
between  the  mantle  and  foot  (Jig.  80). 
y  The  mouth  is  in  the  form  of  a  proboscis 
t  or  trunk,  and  is  surmounted  by  a  small 
triangular  veil,  and  two  tentacles;  they 
have  four  stomachs,  the  second  one  of 
which  is  sometimes  armed  with  bony 
pieces,  and  the  anus  opens  behind  the 
branchise.  One  species,  of  a  lemon 
yellow  colour,  is  found  on  the  coasts  of 
France. 

38.  The  APLYSUE,  which  the  ancients 
called  sea-hares,    have  a  very  singular 
form ;   the     body   resembles   that   of   a 
sort  of  Limax ;   but   the   edges   of   the 
foot,  erected  in  flexible  crests,  surround 
the  back  and  may  be  even  reflected  over 
it.     Their  head  is  supported  by  a  neck 
of  greater  or  less  length,  and  furnished 
with  four  tentacles  (fig.  81,  f),  the  two 
upper  ones  being  hollowed  like  the  ears 
of  a  quadruped,   and  placed   above   the 

eyes  (y).      The   branchiae,   in   the   form  of  very   complicated 


Fig.  81. — APLYSIA. 


Explanation  of  Fig.  80. — m.  the  mantle,  raised  up  to  show  the  branchiae, 
br ; — a.  the  anus  ; — b.  the  mouth  and  trunk ; — v.  the  veil ; — t.  the  tentacles ; 
—p.  the  foot. 

Explanation  of  Fig.  81. — £,  t.  the  tentacles ; — y.  the  eyes ; — m.  the  mantle  ; 
— b.  the  branchice. 

37.  What  are  the  characters  of  the  genus  Pleu'robranchus  ?     (Pleuro- 
branchus,  from  the  Greek,  pleura,  side,  and  bragchia,  gills.) 

38.  What    are  the  characters  of  the  genus  Ap/y'sia?    (Aplysia,  from 
the  Greek,  aplusia,  uncleanness.) 


64 


DOLABELLA.— AKERA. 


6. it~ 


leaflets,  are  fixed  upon  the 
back,  by  means  of  a  broad 
membranous  pedicle,  and 
^  covered  by  a  small  mantle 
r  (m),  in  the  thickness  of 
which  we  find  a  small 
horny  shell.  And  the  anus 
is  situate  behind  the  bran- 
d  chia3.  These  mollusks  live 
on  fucus,  and  are  provided 
f]e  with  an  enormous  crop, 
and  three  other  stomachs 
g  (fig.  82,  d),  the  second 
and  third  of  which  are  arm- 
^  ed  internally  with  sharp 
hooks,  and  cartilaginous 
plates.  A  particular  gland 
secretes  an  acrid  liquor,  and 
pours  it  out  through  an 
opening  situate  on  the  right 
side.  A  purple  coloured 
liquid  exudes  sweats 
from  the  edge  of  the 
mantle,  when  the  animal 
contracts,  and  is  sufficient 
in  quantity  to  dye  the 
water  to  a  considerable  distance  around  it.  Several  species 
of  Aplysiee,  which  vary  in  colour,  are  found  on  the  coasts 
of  France. 

39.  The  DolabellcB   do  not   differ   much  from   the  Aplysia?, 
except  in  the  position  of  their  branchia3,  and  their  mantle  at  the 
posterior  extremity  of  the  body.     They  are  found  in  the  Medi- 
terranean as  well  as  in  the  Indian  seas. 

40.  The  Akera  (fig.  83)   also  resemble  the   Aplysise  in  the 
complication  and  armature  of  the  stomach,  as  well  as  in  the  posi- 
tion of  their  branchia3,  and  several  other  important  points  of  their 
organization  ;  but  they  are  distinguished  by  their  tentacles,  which 
are   short,  very  thick,  and   so  arranged  as  to  form  together  a 


Fig.  82. — APLYSIA. 


Explanation  of  Fig.  82. — Anatomy  of  the  Aplysia  : — a.  the  head  ; — b.  the 
pharynx  ; — e.  oesophagus ; — d.  the  three  stomachs  ; — c.  the  intestines  ;— /. 
the  nervous  collar  surrounding  the  oesophagus ; — g.  the  heart ; — h.  the 
branchise  ; — i.  the  liver  ; — j.  the  anus ; — k.  the  bladder  : — I.  the  ovary. 

39.  What  is  Dolabe'lla  1  (Dolahella,  Latin,  a  little  axe  or  hatchet.) 

40.  How  are  Ake'ras  distinguished  from  the  Aplysiae  1  (Akera,  from  the 
Gjeek,  a,  without,  and  keras,  horn.) 


NUDIBRANCH  GASTEROPODS. 


Fig.  83. BULLA    HYDATIS. 


large  fleshy  shield  above  the  eyes 
(fig.  83,  v).    Many  of  these  ani-  P 
mals  effuse  a  purple  liquid.    Some 
are  entirely  unprovided  with  shell,    v~ 
or  have  only  the  vestige  of  a  shell : 
these  are  the  Akera  properly  so 

called  i  others  have  a  shell  some-  f d 

what  rolled  upon  itself,  and  with- 
out a  projecting  spire  or  notch, 
which  is  concealed  in  the  thick- 
ness of  the  mantle ;  these  form  the  genus  Bullcea ;  and  there 
are  still  others  in  which  the  shell,  onfy  covered  by  a  slight  epi- 
dermis, is  more  convoluted  and  sufficiently  large  to  afford 
a  retreat  for  the  animal :  these  constitute  the  division  of 
Bvlla. 

ORDER  OF    GASTEROPODA    NUDIBRANCHIATA. 

41.  The  mollusks  composing  this  group  are  without  a  shell 
and  carry  their  branchiae  on  some  part  of  the  back  (fig*  84). 
The  structure  of  some  of  their  internal  organs  approximates 
them  to  the  Pulmonea,  the  Inferobranchiata,  and  the  Tectibran- 
chiata  ;  they  all  inhabit  the  sea. 


Fig.  84.7— EOLIDIA. 

42.  Among  the  genera  possessing  this  kind  of  organization, 
we  will  cite  the  Doris,  the  general  form  of  which  is  nearly  the 
same  as  that  of  the  Pleurobranchus  (fig-  83),  and  in  which  the 
branchise  are  inserted  in  a  circle  around  the  anus,  at  the  pos- 
terior part  of  the  back  ;  the  TRITONIA,  in  which  the  branchiaB, 
in  form  of  miniature  trees,  are  attached  along  the  two  sides  of 

Explanation  of  Fig.  83.— Animal  of  the  Bulla  liydatis  :—c.  the  shell ; — 
p,  p.  the  two  lobes  of  the  foot ; — d.  posterior  part  of  the  foot : — v.  the  sort  of 
veil  formed  by  the  union  of  the  tentacles  ; — a.  the  anus. 


41.  What  are  the  characters  of  the  Nudi'branch  gasteropods  ?     (Nudi- 
branch  ;  from  the  Latin,  nudus,  naked,  and  bronchia,  gills.) 

42.  What  are  the  characters  of  the  genus  Glau'cus  ?   (Glaucus ;  from  the 
Greek,  glaukos,  blue.)    What  are  the  characters  of  the  Eolidia  ? 

6* 


66 


GLAUCUS.— C  ARIN  ARIA. 


the  back,  and  in  which  the  mouth  is 
armed  with  lateral  horny  jaws,  similar 
to  shears ;  the  GLATJCUS,  remarkable 
for  its  blue  colour  (Jig.  85),  in  which  ;.'._ 
the  branchiae,  three  pairs  in  number, 
are  situated  in  the  same  manner,  but 
each  one  is  composed  of  several  long 
fringes,  spread  like  a  fan  ;  and  the 
EOLIDI^E  (fig.  84),  which  resemble 
small  Limaces  in  form,  in  which  the 
branchia?  are  composed  of  laminse,  or 
leaflets,  arranged  like  scales,  more  or 
less  crowded  together  on  each  side 
of  the  back.  They  are  found  in 
every  sea. 


Fig.  85. — GLAUCUS. 


ORDER    OF    GASTEROPODA    HETEROFODA. 

43.  These  gasteropods  are  not  organized,  like  all  the  pre- 
ceding, for  crawling  on  the  belly,  but  for  swimming  only.  In 
fact,  their  foot,  in  place  of  forming  a  horizontal  fleshy  disk,  is 
compressed  into  a  vertical  membranous  plate,  which  is  used  as  a 
fin.  Their  body  is  formed  of  a  transparent,  gelatinous  sub- 
stance, and  their  branchiae  are  placed  on  the  posterior  part  of  the 
back. 

The  principal  genera  of  this  group  are  the  CARINARIA  and 

FlOROLA. 

ye  br  c 


p  v 

Fig.  86. — CARINARIA    MEDITERRANEA. 


Explanation  of  Fig.  86. — 6.  the  mouth  ; — t.  the  tentacles ; — y.  the  eyes ; — 
e.  the  stomach ;— f.  the  liver ; — c.  the  shell ; — br.  the  branchiae ; — p.  the  foot ; 
— v.  a  small  sucker  situate  on  the  side  of  the  foot. 


43.  What  are  the  characters  of  the  Heteropo'da  ?    (Heteropoda ;  from  the 
Greek,  eteros,  various,  and  pous>  foot.) 


PTEROPODA. 


67 


44.  The  CARINARI^E  have  the  abdomen  (that  is  to  say,  a 
kind  of  sac  enclosing  the  heart,  the  liver  and  some  other  organs) 
covered  by  a  symmetrical  and  conical  shell,  the  apex  of  which 
is  curved  backwards,  and  the  anterior  edge  covers  the  base  of  the 
branchiae  (Jig.  86,  br}.  There  is  one  species  in  the  Mediterra- 
nean, but  three  have  been  discovered. 

The  FIOROLJE  have  no  shell,  but,  in  other  respects,  very  much 
resemble  the  Carinarise. 

CLASS   OF  MOLLTJSCA   PTEROPODA. 

45.  The  mollusks  composing  this  group 
are  organized  for  swimming  only:  they 
possess  no  organ  by  means  of  which  they 
can  crawl,  or  even  attach  themselves  to 
submarine  bodies,  but  continually  float  in 
the  sea,  and  move  by  the  assistance  of  fins, 
placed  like  wings  on  each  side  of  the  mouth 
(fg.  87).  They  are  all  of  small  size, 
and  most  of  them  inhabit  the  seas  of  warm 
countries ;  but  they  arc  also  found  in  the 
neighbourhood  of  the  poles.  The  Clio 
borealis,  for  example,  abounds  so  exten- 
Fig.  87 — HYALEA.  sively  in  the  arctic  regions,  that,  in  spite 
of  their  very  small  size  (scarcely  an  inch  long),  they  become, 
in  certain  seasons,  the  ordinary  food  of  whales.  Their  form 
varies  much  :  some  of  them  are  naked ;  others  are  provided  with 
a  shell.  They  constitute  several  genera,  the  principal  of  which 
are  the  Clio,  Hyalea,  Cleodora,  Cymbulia,  &c. 


44.  What  are  the  characters  of  the  genus  Carina'ria  ?     (Carinaria  ;  from 
the  Latin,  cari'na,  a  keel.) 

45.  How  are  the  Pte'ropoda  characterized  ?    (Pteropoda ;  from  the  Greek, 
pteron,  wing,  and  pous,  foot.) 


LAMELLIBRANCH  MOLLUSKS. 


LESSON  V. 

CLASS   OF   MOLLUSCA  ACEPHALA,  or,  LAMELLIBRANCHIATA.— 

Organization — Classification. 
FAMILY  OF   OSTRACEA. — Classification — Oysters — Gryphcea — 

Pecten — Lima — Malleus — Anomia  —  Spondylus  — Perna  — 

Etheria — A  vicula  — Pearls — Pearl  fishery — Pinna — .Area— 

Pectunculus —  Trigonia. 
FAMILY  OF  MYTILACEA. — Mussels  (Mytilus)— ModioZws — Ano- 

donta — Unio. 
FAMILY  OF  CHAMACEA. — Tridacna — Chama — Isocardia. 

CLASS   OF  1MOLLT7SCA  LAMELLIBRANCHIATA. 

1.  All  the  mollusks  we  have  heretofore  considered  have  a  dis- 
tinct head ;  those  we  have  yet  to  mention  are  without  this  part, 
and   their   whole   organization    is    of   the  simplest   kind.     The 
mouth  is  always  concealed  at  the  bottom  of  the  mantle,  or  be- 
tween its  folds :  they  hfave  neither  teeth  nor  eyes.     The  nervous 
system  is  very  simple,  and  the  organs  of  locomotion  are  very 
incomplete  or  lamellibranch. 

2.  In  animals  which  form  the  class  of  acephalous  mollusks 
(called  by  Lamarck  Mollusca  conchifera),  the  mantle  is  very 
large  and  folded  in  two,  so  as  to  enclose  the  body,  as  the  leaves 
of  a  book  are  enclosed  by  its  covers.    Sometimes  these  two  leaves 
are  free  at  their  inferior  edge,  sometimes  united  so  as  to  con- 
stitute  a    tube    (fig*  88,  ts,  ti).      A    shell,  composed   of    two 
pieces,  called  valves,  covers  this  mantle  entirely  or  in  part,  and 
at  its  superior  part  there  is  a  hinge  furnished  with   an  elastic 
ligament,  the  play  of  which  causes  the  valves  to  gape  whenever 
the  muscles  (ma,  mp),  which  extend  from  one  valve  to  the  other, 
do  not  contract  so  as  to  keep  them  shut.     The  branchiae  (br) 
are  in  form  of  great  leaves,  transversely  and  regularly  striated  ; 
they  are  always  four  in   number,  and    placed  between  the  in- 
ternal face  of  the  mantle  (or  pallial  membrane)  and  the  body  of 
the  animal.     The  mouth  is  at  one. of  the  extremities  of  the  body, 
and  has  on   each   side   of  it    two   small   triangular  bodies  (£), 
which  are  formed   by  the  extremities  of  the  lips  and  serve  as 
tentacula ;    the  stomach,  liver,  and   other   viscera,   are   lodged 
between   the   mouth    and   anus,   and    beneath    the   heart    (co), 
which  is  situate  on  the  back ;  and  the  lower  part  of  the  body 

1.  What  is  the  distinguishing  feature  of  the  lamellibra'nch  mollusks? 
(Lamellibranch ;  from  the  Latin,  lamella,  a  thin  plate,  and  bronchia,  gills.) 

2.  What  are  the  general  characters  of  acephalous  mollusks  ?  (pronounced 
a-Jcef-alus  ;  from  the  Greek,  a,  without,  and  kephalc,  head. 


ANATOMY  OF  A  MACTRA. 


Fig.  88. ANATOMY    OF    A.  MACTRA. 


Explanation  of  Fig.  88. — Anatomy  of  a  rnactra ;  one  valve  of  the  shell, 
the  corresponding  half  of  the  mantle  and  the  branchiae  have  been  removed 
on  the  left  side  : — c.  the  shell ; — wi.  the  mantle ; — ma.  the  anterior  muscle ; 
— mp.  the  posterior  muscle ;— b.  the  mouth; — t.  the  tentacle;— e.  the  sto- 
mach;—as.  appendix  of  the  stomach  ; — i.  the  intestines  ;— /.  the  liver  ;— p. 
the  foot ; — co.  the  heart  traversed  by  the  rectum  (r) ; — ts.  the  superior  tube 
into  which  the  anus  (a)  opens  ; — ti.  the  inferior  or  respiratory  tube ;— br.  the 
branchiae  of  the  right  side  ; — ga.  the  anterior  ganglia ; — na.  nerves  arising 
from  them; — ng.  inter-ganglionic  nerves; — gp.  posterior  ganglia; — np~ 
nerves  arising  from  them  and  distributed  to  the  mantle. 


70 


DIVISION  OF  TH±,  ACEPHALA. 


is  almost  always  prolonged  into  a  fleshy  mass  (/?),  called  the 
)  which  serves  for  motion,  and  sometimes  has  at  its  base  a 
undle  of  horny  threads,  called  byssus>  by  means  of  which  the 
animal  fixes  itself  to  submarine  bodies. 

3.  This  class  is  divided  into  five  great  families,  which  may  be 
recognised  by  the  following  characters  : 

(FAMILIES.) 

f  having  the  mantle  open,  and  without  tubes  or  particular  \  ^ 
apertures.  \ 

open  in  front,  and  having"} 

but  one  separate  aperture  UYTILACEA< 

for   the   escape  of   excre-  I 

fnent.  J 


rnot  prolonged 

so  as  to  form 

tubes.        The  " 

having    the 

mantle 

mantle 

closed      be- 

hind, so  as 

to  form  par-  < 

ticular 

,  openings. 

prolonged    so 

as  to  form  two 

tubes.       The  " 

mantle 

closed  and  pierced  by 
three  apertures,  the  first 
of  which  serves  for  the 
passage  of  the  foot,  the 
second  for  respiration,  and 
the  third  for  the  exit  of 
excrement. 


CHAMACEA. 


open  in  front  and  present-  J  CARDIACEA> 
ing  two  tubes  behind.  ^ 

closed,  and  not  having,  in  "j 
front  or  below,  but  a  single  I 
opening  for  the  passage  of  >  INCLUSA. 
the  foot,  and   behind,  two  j 
tubes. 


4.  The  FAMILY  of  OSTRACEA  has  the  oyster  for  its  type, 
and   is   composed   of  a   great   number   of  mollusks,   that   are 
entirely  without  a  foot,  or  having  a  very  small  one  only,  and 
which,  for  the   most  part,  live  attached  to   submarine   bodies, 
either  by  their  shell  or  by  their  byssus.     The  mantle  is  open 
behind  as  well  as  in  front,  and  its  two  lobes  are  nowhere  united 
to  form  particular  openings,  as  we  have  remarked  in  all  other 
acephala. 

5.  This  group  is  divided  into  two  tribes,  according  as  there 
is  a  single  muscle,  going  from  one  valve  to  the  other,  or  two 

3.  Into  how  many  families  is  the  class  of  lamellibranch  mollusks  divided  ? 

4.  What  are  the  characters  of  the  family  of  Ostra'coa  ?    (From  the  Latin, 
ostrea,  an  oyster.) 

5.  What  is  the  distinguishing  character  of  the  tribe  of  Mono'mya'ria  ? 
(Mono'mya'ria.    From  the  Greek,  monos,  single,  and  rawon,  muscle.)    How 
is  the  tribe  of  Di'mya'ria  distinguished  ?     (Di'mya'ria.     From  the  Greek, 
dis,  two,  and  mudn,  muscle.) 


OYSTERS. 


71 


of  these  organs,  one  placed  near  the  anus  and  the  other  in  front 
of  the  mouthf,  an  arrangement  which  exists  in  nearly  all  other 
acephala.  The  first  tribe,  in  which  there  is  but  one  muscle,  is 
called  Monomyaria,  and  the  second  Dimyaria. 

6.  To  the  first  of  these  divisions  belong  the  OYSTERS,-— 
Ostrea.  The  shell  of  these  mollusks  is  irregular,  laminated,  and 
composed  of  two  unequal  valves,  united  by  a  short  ligament 
lodged  at  either  extremity  in  a  pit,  and  the  hinge  is  without  teeth 
or  projecting  lamina.  The  structure  of  the  animal  itself  is 


c  a 

0  Fig.  89. ANATOMY  OF  AN  OYSTER. 

very  simple.  Its  mantle,  the  lobes  of  which  are  united  above 
near  the  hinge  (6),  has  a  double  fringed  border  :  there  is  no 
appearance  of  foot.  The  adductor  muscle  (e)  of  the  valves  (com- 
monly called  the  heart),  is  situate  near  the  centre  of  the  body, 
and  the  heart  (Z),  instead  of  being  placed  as  usual  on  the  back, 

Explanation  of  Fig.  89. — Anatomy  of  an  oyster ;— a.  one  of  the  valves  of 
the  shell ;— 6.  the  hinge  ;— c.  mantle  of  the  left  side ;— d.  portion  of  tho 
right  lobe  of  the  mantle  ; — e.  the  muscle  ;— f.  the  mouth ; — g.  the  labial 
tentacula ;— h.  the  liver ; — i.  the  intestine  :— j.  the  anus ;— k.  the  branchiae  ; 
— /.  the  heart. 


6.  What  are  the  characters  of  the  family  of  Ostracea?  Where  are  oysters 
found? 


72  OYSTERS. 


is  found  between  this  muscle  and  the  mass  of  the  viscera,  where 
it  is  readily  distinguished  by  the  brown  colour  of  its*auricle ;  the 
mouth  is  concealed  under  a  sort  of  hood,  formed  by  the  union  of 
the  upper  portion  of  the  two  lobes  of  the  mantle;  the  tentacles, 
which  surround  this  opening,  closely  resemble  the  branchiae, 
which  are  large  and  cover  the  whole  abdomen;  and  the  anus  is 
seen  above  the  muscle.  All  these  mollusks  have  an  ovary  and 
produce  eggs,  which,  at  the  time  of  laying,  are  extremely  small 
and  suspended  in  a  whitish  liquid,  the  appearance  of  which  is 
analogous  to  that  of  minute  drops  of  tallow.  This  spawn 
floats  on  the  water  and  soon  adheres  to  neighbouring  shells  or 
some  other  submarine  body :  and  the  young  oysters  are  always 
adherent,  either  to  each  other  or  to  an  adult  oyster  or  to  the  rocks 
on  which  they  live  ;  but,  in  the  first  case,  they  generally  detach 
themselves  as  they  advance  in  age,  and  form  extensive  masses 
which  are  called  beds  or  banks.  Their  growth  is  very  rapid. 
We  are  assured  that  at  the  end  of  three  months  after  being 
spawned,  they  are  of  the  size  of  a  quarter  of  a  dollar,  and  at 
the  end  of  the  first  year,  they  are  about  two  inches  in  diame- 
ter ;  and  in  three  years  they  attain  to  about  three  inches  in 
length.  Nothing  is  precisely  known  of  the  duration  of  their 
existence. 

7.  Many  species  of  oysters  are  described  :  the  most  interest- 
ing and  most  extensively  diffused  is  the  Ostrea  edulis — the 
edible  oyster ;  it  affords  us  a  wholesome  and  agreeable  article  of 
diet,  and  its  consumption  has  been  immense  since  the  remotest 
antiquity.  These  mollusks  are  ordinarily  found  in  great 
numbers  together,  forming  beds  of  considerable  extent,  situate 
near  sea  coasts,  in  bays  or  estuaries,  or  in  localities  where 
the  sea  is  not  very  deep.  They  are  objects  of  active  pursuit, 
and  are  caught  by  means  of  a  kind  of  rake  with  a  net  attach- 
ed, called  a  drag,  or  dredge,  which  is  drawn  over  the  joyster- 
bed ;  or  where  the  water  is  shallow,  they  are  taklh  up  by  long 
tongs  of  a  suitable  formation  :  in  France,  after  being  caught  they 
are  not  immediately  consumed,  but  are  placed  (planted  out) 
in  particular  basins,  where  they  are  kept  for  a  time,  and  where  they 
fatten  and  acquire  a  more  delicate  flavour.  The  largest  are 
usually  taken  from  the  shell  and  pickled  ;  but  the  others  are 
eaten  without  preparation,  and  are  esteemed  by  many  only 
while  alive.  In  fact  their  preservation  for  any  length  of  time 
is  prevented  by  the  habit  these  animals  have  of  closing  the 
shell  as  soon  as  they  are  taken  out  of  the  water.  When  dead 
their  shell  remains  open. 


7.  How  are  oysters  caught  1 


GRYPH.EA.— PECTEN.  73 

8.  European  oysters  possess  a  much  more  decided  flavour,  a 
stronger  taste,  than  those  of  the  United  States ;  Americans,  on  first 
eating  oysters  in  London  or  Paris,  commonly  complain  of  their 
strong  coppery  taste,  and  it  is  not  until  after  several  trials  they 
learn  to  prefer  them  to  our  own.     The  locality  of  oyster  beds 
exercises  a  great  influence  over  the  taste  of  the  oyster ;  within 
the  tropics  they  are  rarely  found  good,  and  they  are  almost  un- 
known in  the  Pacific  Ocean.     Oysters  taken  near  the  entrance 
of  the  Chesapeake  and  Delaware  Bays  have  a  high  reputation, 
and  are  consumed  in  great  quantities.     Norfolk  oysters  are  pro- 
verbially excellent. 

The  markets  of  Paris  and  the  north  of  France  are  chiefly 
supplied  from  the  bay  of  Cancale;  from  which  the  boats  of 
Houlle,  near  Cancale,  and  Granville,  carry  away  more  than 
eighty  millions  of  these  mollusks  every  year,  the  major  part  of 
which  are  sent  to  Courseulles  and  other  parts  of  Normandy, 
where  there  are  considerable  establishments  for  the  parkage 
(planting  out)  of  oysters,  whence  they  are  sent  post  to  Paris. 
About  the  beginning  of  summer  these  mollusks  cast  their  spawn : 
at  this  season  it  is  customary  not  to  eat  them,  and  it  is  generally 
believed  they  are  then  unwholesome,  but  this  opinion  does  not 
appear  to  be  well  founded. 

9.  We  give  the  name  of  GRYPHUEA  to  shells,  which  for  the 
most  part  are  fossil,  and  which  are  very  analogous  to  oysters, 
but   the   convex  valve  is  more  pro- 
jecting at  the  apex  or  beak,  and  at 

that  point  bends  into  a  hook  (fig.  90). 
They  are  found  in  very  ancient  for- 
mations. There  is  but  one  living 
species  known. 

10.  The  SCALLOPS — Pecten  (also 
called  the  pilgrim's  shell,  from  being 

worn  as  an  ornament  by  pilgrims) —  Fl&'  9^*    GRYP1LEA- 

resemble  the  oysters  in  the  disposition  of  the  hinge,  and  may 
be  easily  recognised  by  their  inequivalve,  semicircular  shell, 
almost  always  marked  by  ribs,  radiating  from  the  apex  of  each 
valve  towards  their  margin,  and  having  on  each  side  of  the 
hinge  an  angular  enlargement  called  the  ear  (Jig.  91,  e).  In 
some  species  of  Pecten  there  is  a  byssus ;  but  most  of  these  mol- 


8.  How  do  European  oysters  differ  from  those  of  the  United  States  ? 

9.  What  is  the  character  of  the  Gryphae'a  ?  (Gryphsea  ;  from  the  Greek, 
grvpos,  incurved.) 

10.  What  are  the  characters  of  the  genus  Pecten?  (Pecten,  Latin,  a 
comb.)     What  is  meant  by  the  ear  of  a  shell  ? 


74 


MALLEUS.— ANOMIA.— SPONDYLUS. 


Fig.  91. PECTEN  JACOB^EUS. 

and  Pedum,  the  shells  of 
what  resembling  the  shell 
of  the  Scallop  in  their  gene- 
ral form : 

1 1 .  The  Hammer  Oys~ 
ters— Malleus  (fig.  92) — 
which  have  a  notch  near 
the  hinge  for  the  passage 
of  a  byssus :  the  shell  is 
irregular  and  the  ears  are 
prolonged,  making  its 
shape  slightly  resemble  a 
hammer :  the  ANOMIJS, 
in  which  the  interior  valve 
is  deeply  notched  (fig.  93) 


lusks  are  not  adherent,  and  can  even 
swim  with  considerable  rapidity  by 
suddenly  closing  their  valves.  The 
mouth  is  furnished  with  many 
branched  tentacula,  which  take  the 
place  of  labial  lamelhe,  and  be- 
tween the  branchias  there  is  a  small 
oval  foot.  St.  James'  Pecten  is 
found  on  the  coast  of  France.  The 
species  of  this  genus  are  very  nu- 
merous and  are  very  generally  dif- 
fused. 

The    following    genera    are    also 

placed    among   the   oysters ;    Lima 

which  are  oval  or  oblong  and  some* 


93. — ANOMIA. 


Fig.  92. — MALLEUS. 

alongside  of  the  ligament,  permitting 
the  central  part  of  the  muscle  to  pass 
through  it  to  be  inserted  into  a  plate, 
sometimes  horny,  sometimes  stony, 
by  aid  of  which  the  animal  attaches 
itself: 

12.  SPONDYLUS,  in  which  the 
shell  is  foliated  or  even  spiny,  and 
on  each  valve  at  the  hinge  there 
are  two  teeth  which  are  received 
into  pits  in  the  opposite  valve : 


11.  What  are  the  characters  of  the  genus  Ma'lleus  ?    (Malleus,  Latin,  a 
hammer.)     What   are  the   characters  of  the   genus  Ano'mia  ?    (Anomia ; 
from  the  Greek,  a,  without,  and  nomos,  law  ;  because  not  easly  placed  accor- 
ding to  the  laws  of  classification.) 

12.  How  is  the  genus  Spo'ndylus  known  ?  (Spondylus,  Latin,  a  spindle, 
or  shellfish.) 


PERNA — ETHERIA.— AVICULA.  75 

13.  PERNA  (fig.  94),  in 
which  the  hinge  is  composed 
of  several  ligaments  inserted 
into  particular  pits;  besides 
a  great  many  other  shells, 
either  recent  or  fossil. 

Among  the  Oslracea 
provided  with  two  distinct 
muscles,  and  the  shells  con- 
sequently marked,  on  the 
internal  surface  of  each 
valve,  by  two  irregular  sur- 
faces (muscular  depressions) 

corresponding  with  the  in-  &£•  94>    PERNA- 

sertion   of   these   organs,   we   will   mention  Etheria,    Avicula, 
Pinna,  Area,  and  Trigonia. 

14.  The  EtherifB  are  very  analogous  to  oysters  :  their  shell  is 
large,  inequivalve,  very  irregular,  without  teeth  at  the  hinge  and 
provided  with  a  ligament,  which  is  partly  internal  and    partly 
external.     They  are  very  rare  shells,  and  have  been  overlooked 
by  travellers  from  being  attached  to  rocks  at  considerable  depths. 
They  inhabit  the  East  Indian  seas. 

15.  The  AVICUL^E  are  recognised  by  their  inequivalve  shell, 
with  a  rectilinear  hinge  furnished  with  a  narrow  ligament,  and 

frequently  elongated 
into  wings  at  its  two 
extremities  (fig-  95). 
The  body  of  these 
mollusks  is  very  smal  1 
and  prolonged  into  a 
vermiform  and  coni- 
cal foot,  and  furnished 
with  a  byssus,  for 

the  passage  of  which 
Fig.  95,-AvieuLA.  there  ig  a  notch  in  the 

side  of  the  shell.    The  anterior  adductor  muscle  is  extremely  small 
and   the  labial    appendages  very  large.     These  mollusks  have 


13.  What  is  the  genus  Per'na?  (Perna,  Latin,  a  gammon  of  bacon,  a 
shell-fish.) 

14.  What   are  the  characters  of  the  genus  Ethe'ria  ?  (Etheria,  from  the 
Greek,  aithb,  I  shine.) 

15.  How  is  theAvi'cula  recognised?    (Avieula,  from  the  Latin,  avis,  a 
bird ;  because,  when  the  shell  is  widely  open,  it  bears  a  remote  resemblance 
to  a   bird  with  spread  wings.)     How  does  the   genus  Meleagri'na   differ 
from  Avieula  ?   (Meleagri'na ;  from  the  Greek,  meleag'ris,  a  guinea-hen.) 


76 


MELEAGRINA.— PEARLS. 


Fig.  96. MELEAGRINA 

MARGARITiFERA. 


been  divided,  perhaps  without  sufficient  reason,  into  two  genera, 
AVICULA   and    MELEAGRINA,   according    as    the   shell   is    with 

or  without  the  wing-like  prolon- 
gations, and  the  hinge  is  armed 
with  a  tooth  or  unprovided  with  a 
similar  protuberance  :  the  shell  of 
the  latter  is  nearly  equivalve,  and 
the  passage  of  the  byssus  produces 
in  each  valve  a  notch.  The 
Meleagrince  are  more  scaly  ex- 
ternally than  the  Aviculse.  Their 
nacre  is  sometimes  very  thick  and 
very  brilliant ;  and  the  extravasa- 
tion of  the  liquid  destined  for  the 
periodical  augmentation  of  the  in- 
terior of  the  shell,  frequently  gives 
rise  to  isolated  deposits  of  this 
beautiful  nacre,  forming  pearls. 
The  shell  of  the  Pearl  Oyster  is 
nearly  semicircular,  scaly  and  greenish  brown  externally;  it 
grows  to  considerable  size,  and  is  to  be  found  on  the  coast  of 
Ceylon,  in  the  Persian  Gulf,  the  Gulf  of  Mexico,  and  in  many 
other  localities,  where  it  occurs  in  extensive  beds,  attached  by 
its  byssus  to  submarine  rocks :  it  is  the  object  of  an  active 
fishery. 

16.  Pearls,  as  stated  above,  are  bodies  of  the  same  nature 
as  the  brilliant  nacre  lining  the  shell :  they  are  composed  of 
concentric  layers  of  nacre  very  closely  applied  one  over  the 
other,  like  the  coats  of  an  onion,  and  are  produced  whenever 
this  matter,  instead  of  being  spread  out  in  thin  layers  over  those 
already  deposited,  constitutes  small  isolated  masses  like  little 
drops,  or  adhering  to  the  shell  by  a  mere  pedicle.  Their  for- 
mation depends  upon  a  kind  of  disease,  or,  at  least,  upon  an 
anomalous  activity  of  the  secretory  process  which  gives  rise  to 
nacre  :  hence  every  circumstance  that  stimulates  this  secretion, 
such  as  the  presence  of  a  grain  of  sand  or  other  foreign  body 
betwixt  the  shell  and  the  mantle  of  the  animal,  tends  to  bring 
about  this  formation.  Pearl  Oysters  are  not  the  only  mollusks 
that  produce  pearls.  All  shells  that  are  internally  nacreous 
may  contain  them.  Patella?,  Haliotides,  and  our  common  mus- 
sels sometimes  contain  them,  and  it  is  not  uncommon  to  find 
them  in  a  sort  of  large  mussel  (Unio)  which  inhabits  the  great 
rivers  of  northern  Europe  and  the  United  States ;  but  the 


16.  What  are  pearls  ? 


PEARL  FISHING.  77 


Meleagrinse  furnish  the  greatest  quantity  and  yield  the  most 
beautiful  pearls. 

17.  The  chief  pearl  fisheries  are  in  the  Gulf  of  Manaar  on  the 
coast  of  Ceylon,  in  the  Persian  Gulf,  the  Gulf  of  Panama,  and 
on  the  coast  of  California ;  but  there  are  banks  of  Meleagrinse 
(pearl  oysters)  in  many  other  localities,  sucfy  as  the  coasts  of 
Japan,  Cumana,  &c.  To  obtain  these  precious  mollusks,  men 
accustomed  to  the  exercise  dive  to  the  bottom  of  the  sea  and 
collect  them  at  depths  of  from  twenty  to  fifty  feet.  To  accel- 
erate his  descent  the  diver  seizes  a  stone  (weighing  from  15  to 
25  pounds)  with  his  toes,  and  on  reaching  the  bottom  he  aban- 
dons the  diving  stone  (which  is  drawn  up  by  attendants  in  the 
boat,  to  be  prepared  to  take  him  down  again),  clings  to  the 
ground,  and  begins  to  fill  a  net  which  he  carries  down  with  him 
for  the  purpose.  When,  from  the  necessity  of  breathing  or  fear 
of  sharks,  he  wishes  to  ascend,  he  checks  the  cord  of  the  net, 
which  is  instantly  felt  by  the  attendants,  who  commence  pulling 
up  as  fast  as  they  are  able  ;  the  diver  remains  with  the  net  until 
it  is  so  far  clear  of  the  bottom  as  to  be  in  no  danger  of  upsetting, 
and  then  commences  hauling  himself  up  by  the  cord  (hand 
over  hand),  which  his  attendants  are  likewise  pulling ;  when  by 
these  measures  his  body  has  acquired  an  impetus  upwards,  he 
forsakes  the  cord  and  rapidly  ascends  to  the  surface,  swims  to 
his  diving  stone,  aad  by  the  time  the  contents  of  his  net  have 
been  emptied  into  the  boat,  he  is  ready  to  go  down  again.  One 
diver  will  take  up  in  a  day  from  one  to  four  thousand  oysters. 
The  diver  seldom  exceeds  a  minute  under  water;  the  more 
common  time  is  from  53  to  57  seconds.  In  order  that  the  banks 
may  not  be  devastated,  they  are  under  regulation,  and  it  is  sup- 
posed that  seven  years  are  required  for  the  oyster  to  attain  its 
full  size.  At  Ceylon  the  fishing  season  lasts  from  the  middle  of 
February  to  the  end  of  March. 

"  During  this  period,  the  shores  of  Arippo  are  enlivened  by  crowds  of 
people  from  all  parts  of  the  country ;  divers,  boat-owners,  speculators,  and 
the  curious,  assemble  to  behold 

4  Pale  glistening  pearls,  and  rainbow-colour'd  shells,' 

while  the  lapidary  attends  with  his  wooden  stand  and  bow,  to  drill  the 
pearls  and  fit  them  to  be  strung1,  so  soon  as  they  are  got  out  of  the 
oyster,  which,  according-  to  all  accounts,  is  a  tedious  and  rather  disgusting- 
operation.  The  oysters  are  put  into  pens,  and  there  left  until  the  animal 
matter  becomes  softened  by  putrefaction,  when  it  is  subjected  to  frequent 
washing-s,  and  the  pearls  shine  forth,  emblems  of  purity  in  the  loathsome 
mass.  Some  are  of  a  bluish,  some  of  a  yellowish,  and  some  of  a  whitish 
lustre  ;  each  class  finds  a  ready  market  among  its  admirers;  in  the  East, 
the  bluish  and  yellowish  varieties  are  most  prized,  but  in  the  eyes  of  the 
Christian  fair  the  pure  white  shines  brightest." — Ruschenberger's  Voyage 
round  the  World. 

17.  How  are  pearls  obtained  ? 

7* 


78 


PINNA.— ARCA.— PECTUNCULUS. 


The  annual  revenue  from  the  pearl  fishery  of  Ceylon  is  esti- 
mated at  about  $80,000. 

18.  The  PINNAE  have  two  equal  valves  in  form  of  a  half-open 
fan,  gaping  and  united  by  a  ligament  along  one  of  their  sides. 
A  very  large  species  is  found  in  the  Mediterranean,  which  lives 
half-buried  in  the  sand,  and  anchored  by  its  byssus,  the  fila- 
i  ments  of  which,  being  very  strong,  fine,  and  brilliant  as  silk,  are 
employed  by  the  inhabitants  of  some  parts  of  Calabria  and  Sicily 
in  the  manufacture  of  precious  stuffs. 

19.  The  ARC^E  are  dis- 
tinguished from  all  the 
preceding  by  their  equi- 
valve  shell.  The  hinge 
which  extends  along  the 
side  of  the  valves  is 
studded  with  a  great  many 
little  teeth,  which  fit  into 
the  intervals  of  those  of 
Fig.  97.— ARCA.  the  0ppOSite  side  recipro- 

cally ;  in  some,  the  ARCA  PROPERLY  so  CALLED  (fig.  97),  the 
hinge  is  rectilinear,  and  the  shell  is 
longer  in  -a  direction  parallel  to 
this  junction ;  in  others,  named 
PECTUNCULUS  (fig.  98),  the  hinge 
is  curved,  and  the  shell  is  lenticu- 
lar in  form.  The  first  are  met  with 
near  the  shore  in  rocky  situations, 
and  are  ordinarily  covered  by  a 
hairy  epidermis ;  the  latter  live  in 
the  mud. 

20.  Finally,  the  TRIGONIJE,  most 
of  the  species  of  which  are  fossil, 
are  remarkable  for  their  peculiar 
hinge ;  the  right  valvq  is  furnished 
with  two  projecting  plates,  crenulate  Fig.  98.— PECTUNCULUS. 


18.  What  are  the  characters  of  the  genus  Pi'nna?     (Pinna,  Latin,  & 
fin.) 

19.  What  are  the  characters  of  the  genus  Area  ?    What  are  the  charac- 
ters of  the  genus  Pectu'nculus  ?     (Pectunculus,  Latin,  the  diminutive  of 
pecten,  a  comb.) 

20.  What  is  Trigo'nia  ?    (From  the  Greek,  trigonos,  having  three  cor- 
ners.) 


TRIGONIA.— MUSSELS.  79 

on  each  face  (jig.  99), 
and  entering  between 
four  plates  of  the  left 
(opposite)  valve,  like- 
wise crenulated  upon 
their  internal  face 
only.  There  is  but 
one  living  species 
known,  —  Trigonia 
pectinata, — which  in- 
habits the  seas  of  Figt  99._TR1GONiA  PECTINATA. 
New  Holland ;  exter- 
nally, it  has  the  aspect  of  Pecten  without  ears. 

21.  In  the  Family  of  MYTILACEA,  the  mantle  is  widely  open 
in  front,  as  in  the  Ostracea,  but  there  is  a  particular  opening  for 
the  escape  of  excrement ;  this  orifice,  however,  is  not  prolonged 
into  a  tube,  as  in  the  families  that  follow,  and  there  is  no  special 
aperture  for  the  passage  of  water  for  the  purpose  of  respiration. 
There  is   always  a  distinct   foot,  and   the   valves  are  approxi- 
mated by  the  action  of  two  adductor  muscles. 

The  Mytilacea?  resemble  each  other  sufficiently  to  be  commonly 
known  under  the  single  name  of  Mussels,  but  they  require,  never- 
theless, to  be  separated  into  several  genera,  the  most  important 
of  which  are,  Mussels  properly  so  called, — Mytilus, — Anodonta, 
and  Unio. 

22.  MUSSELS  PROPERLY  so  CALLED — Mytilus — abound  on  the 
rocks  of  the  coast  of  France  and  of  other  countries,  where  they 
live  fixed  by  the  byssus,  and   generally  closely  united  to  each 
other.      Their  shell   is  shut,  and  its  valves,  triangular  in  form, 
are  equal,  arched  and  united  by  a  narrow  ligament  on  the  side  of 
their  acute  angle.       The   mouth  of  the  animal  is  situate  near 
the  summit  of  the  shell,  the  opposite  extremity  of  which  gives 
passage  to  the  byssus ;  the  anus  also  is  placed  near  the  hinge ; 
and  opposite  to  this  orifice  there  is  a  particular  opening  or  small 
tube  formed  by  the  mantle;  towards  the  round  angle  of  the  shell, 
where  the  water  necessary  for  respiration  passes,  the  edge  of 
the  mantle  is  fringed ;  and  the  foot  is  slender,  cylindrical,  and 
furnished  behind  with  a  silky  byssus.      Mussels  are  generally 
eaten  as  food,  but  they  sometimes  occasion  a  kind  of  poisoning, 
accompanied    by  very  violent  symptoms,  occasionally  followed 
by  death. 


21.  What  are  the  characters  of  the  family  of  Mytila'cea  ? 

22.  What  are  the  characters  of  the  genus  My'tilus  ?     (From  the  Greek, 
mutilos,  a  mussel.) 


80 


ANODONTA.— UNIO. 


23.  We  distinguish  those  Mussels  which  have  the  hinge  placed 
lower,  under  the  name  of  MODIOLUS,  and  another  is  called 
LITHODOMUS,  which  has  the  shell  almost  equally  rounded  at  both 
ends,  and  excavates  holes  in  stones,  to  which  it  was  at  first  only 
suspended. 


Fig.  100. — ANODONTA. 

ft 

24.  The    ANODONTA    live   in  fresh    waters,  and   are    recog« 
nised  by  their  thin  shell,  moderately  inflated,  oval,  close,  and 
without  teeth  in  the  hinge  (fig.  100);  they  want  the  byssus,  and 
ate   provided  with    a  very  large   foot,  compressed    and   almost 
quadrangular    in  form,  by  means  of  which  they  crawl  on  the 
sand  or  mud.     A  great  many  species  are  found  in  the  great  rivers 
of  the  United  States. 

25.  The  UNIONES  closely  resemble  the  Anodontce,  but  have  a 
more  complicated  hinge,  the  right  valve  having  a  pit  (fossette) 
into  which  a  tooth  of  the  left  valve  penetrates,  presenting  behind 
a    long   lamina,    which,  in    its    turn,    is    received    between  two 
laminae  of  the  opposite  side.     These  mollusks  also  inhabit  fresh 
waters,  but  prefer  those  which  are  running.     A  very  great  num- 
ber of  species  are  found  in  our  Western  waters,  for  the  descrip- 
tion of  most  of  which  we^are  indebted  to  the   labours  of  Mr.  I. 
Lea,  of  Philadelphia. 


23.  What  is  the  genus  Litho'domus  ?     (From  the  Greek,  lithos,  a  stone, 
and  the  Latin,  domus,  a  house.) 

24.  How  is   the   genus   Anodo'nta   recognised?      (Anodonta,   from   the 
Greek,  a,  without,  and  odous,  in  the  genitive  case,  odontos,  a  tooth.) 

25.  What  are   the   characters  of  the  genus  U'nio  ?     (Unio,   Latin,  a 
pearl.) 


FAMILY  OF  CHAMACEA. 


81 


Fig.  101.  —  UNIO. 

We  also  place  in  this  same  group  certain  marine  mollusks, 
which  resemble  the  Unios  in  their  organization  and  the  general 
disposition  of  the  hinge,  but  in  which  the  beaks  (summits)  of 
the  shell  are  more  arched,  and  from  which  projecting  ribs 
radiate  towards  the  circumference  ;  such  are  the  genus  CAR- 
DITA,  the  form  of  which  is  more  or  less  oblong  or  cordiform 
(heart-shape)  ;  the  CYPRICARDIA,  in  which  the  tooth  beneath  the 
summit  of  theshell  is  divided  intotwoor  three  ;  the  CORALLIOPHAGA, 
in  which  the  shell  is  thin  and  the  lateral  plate  much  effaced,  &c. 

26.  In  the  FAMILY  OF  CHAMACEA  the  mantle  is  closed 
and  perforated  by  three  open- 
ings only;  through  the  anterior 
one  passes  the  foot  (fig.  102, 
p)  ;  the  next  (r)  gives  passage 
to  the  water  necessary  for  res- 
piration, and  the  third  (e)  is 
for  the  expulsion  of  effete 
matters.  As  we  have  already 
stated,  the  last  two  openings 
are  not  prolonged  into  tubes,  P( 
as  in  the  next  two  families. 
And  the  hinge  is  very  analo- 
gous  to  that  of  the  Unios  ;  for 
the  left  valve  has  a  tooth  near 
the  summit,  and  funher  back,  a  projecting  plate,  which  are  re- 
ceived into  fossa?  (pits)  in  the  opposite  valve. 

Explanation  of  Fig.  102.—  A  Chama  divested  of  its  shell  to  show  the  dis- 
position of  its  mantle  :—  p.  the  foot  ;  —  r.  opening  for  respiration  ;  —  e.  the 
opening  for  the  passage  of  excrement. 

26.  What  are  the  characters  of  the  family  of  Chama'cea  ? 


,  WITHOUT  ITS  SHELL. 


TRIDACNA.— CHAMA.— ISOCARDIA. 


This  family  is  divided  into  Tridacna,  Chama,  Isocardia,  &c. 
27.  The  TEIDACN^E  have  an  equivalve  shell,  which  is  elon- 
gate and  gaping  in  front,  or  its  edges  are  dentate  (fig.  103). 

Their  internal  orga- 
nization is  remarka- 
ble in  several  particu- 
lars. The  valves  have 
only  a  single  adductor 
muscle.  The  mantle 
~\. ;;  is  widely  open  in  front, 
to  give  passage  to 
the  byssus,  and  a 
little  beneath  the  an- 
terior angle  presents 
Fig.  103.— TRIDACNA.  another  opening,  by 

which  water  is  conveyed  to  the  branchiae;  and  the  third  open- 
ing, which  corresponds  to  the  anus,  is  situate  near  the  middle 
of  the  inferior  border.  To  this  genus  belongs  an  enormous 

shell  of  the  Indian  Ocean,  known 
under  the  vulgar  name  of  the 
Holy-water  Pot ;  it  adheres  to 
the  rocks  by  its  byssus,  which  is 
so  large  sometimes  that  an  axe  is 
required  to  cut  it,  and  the  shell 
itself  occasionally  weighs  over 
three  hundred  pouuds. 

28.  The  CHAMA  have   an  ir- 
regular, equivalve  shell,  which  is 
usually  lamellar  and  rough;  they 
live  attached  to  rocks,  coral,  &c., 
like    oysters,    and    they   have  a 
small  foot  bent  like  that  of  man 
(fig.  102). 

29.  The  JSOCARDIJE  (#§-.104), 
on    the    contrary,   have    a    free, 
regular,  convex  shell  with  spirally 
curved  summits,  divided  anterior, 
ly.    A  large,  smooth,  red  species, 
the    Chama    cor,   inhabits    the 

Fig.  104-isocARDiA.  Mediterranean. 


27.  What  are  the  characters  of  the  genus  Trida'cna  ? 

28.  How  is   the   genus   Chama   distinguished  ?     (Chama, — pronounced 
fca'wjcr, — from  the  Greek,  chad,  I  gape.) 

29.  What  are  the  characters  of  the  genus  Isoca'rdia  ?  (Isocardia,  from 
the  Greek,  isus,  like,  and  kardia,  a  heart, — heart-shape.) 


FAMILY  OF  CARDIACEA. 


83 


LESSON  VI. 

FAMILY  or  CARDIACEA. — Cardium — Donax — Cyclas — Corbis 

—  Tellina  —  Venus — Petricola —  Venerupis — Mactra. 
FAMILY  OF  INCLUSA. —  Lutraria — My  a — Byssomia — Hiatella 

—  Solen —  Sanguinolaria —  Pholas —  Teredo —  Fistulana — 
Gastrochcp.na — Clamigella — Aspergillum. 

CLASS    OF    MOLLUSCA    BRACHIOPODA. — General    Characters— 

Lingulo — Terebratula — Orbicula. 

CLASS  OF  MOLLUSCA  TUNICATA,  or  ACEPHALA  NUDA. — Biphora 
— Ascidia — Botryllus — Pyrosoma. 

CLASS  OF  ACEPHALA,  CONTINUED. 

1.  The  FAMILY  OF  CARDIACEA  is  characterized  by  having 
the  mantle  open  in  front,  and  prolonged  posteriorly  into  twp 
tubes,  which  are  sometimes  ^ 

distinct,  and  at   others   united 
in  a  single  mass  ;  one  of  them     a 
(fiS"  105,  r)  serves  for  respi- 
ration,  and   the   other  (e)  for 
the   passage   of   excrement. — 
This  mode  of  conformation  is  p 
recognised  in  the  shell  by  the 
impression    made    by    the    at- 
tachment  of  the   edge   of  the 
mantle,    called    the    pallia!    line   (jig.    106,    Z),    which    before 

joining    the    posterior    muscular 
•  impression      or     cicatrix      (mi), 
curves   more   or   less    deeply  in- 
I     wards.      In   all    these   mollusks, 
there    is     a    transverse    muscle 
and  a  foot  (fig.  105,  p),  which 
generally  enables   the  animal  to 
crawl.     The  species  of  Cardia- 
cese  that  have  long  tubes,  ordi- 
narily live  buried  in  the  sand  or 
Fig.  106.— VENERUPIS.  mud. 


Fig.  105. — TELLINA. 


ai 


Explanation  of  Fig.  105. — Tellina : — a.  the  shell ; — fc,  the  hinge ; — r.  tube 
for  respiration ; — e.  tube  for  excrement ; — p.  the  foot. 

Explanation  of  Fig.  106. — Veneru'pis  : — 1.  pallial  line  ; — ai.  anterior 
muscular  impression  ; — mi.  posterior  muscular  impression  or  cicatrix. 


1.  How  is  the  family  of  Cardia'cea  characterized  ?  (Cardiacea,  from  the 
Latin,  cardium,  heart.) 


84     CARDIUM.— DONAX.— CYCLAS.— CORBIS.— TELLINA. 

2.  In  this  family  we  place  Cardium,  Donax,  Cyclas,  Corbis, 
Tellina,  Lucina,  Venus,  Petricola,  Mactra,  &c.,  genera  which, 
for  the  most  part,  are  very  numerous  in  species. 

3.  The    CARDIA  —  Cardium — are   chiefly    characterized    by 
the  hinge,  which  consists  of  two  small  teeth  in  each  valve,  situate 
in   the  centre,  and  a  projecting  plate  or  tooth  placed  at  some 
distance  in  front  and  behind.     The  shell  is  equivalve,  convex, 
and   furnished    with   ribs  radiating   from   the   summit   towards 
the  circumference.     And   when   looked    at   from   one   side,  its 
general  form  reminds  us  of  that  of  a  heart,  from  the  manner  in 
which  the  summits  (beaks)  of  the  valves  rise  up,  and  curve  in- 
wards towards  each  other. 

4.  The  DONACES — Donax — have  a  hinge  formed  nearly  like 
that  of  the  Cardia;  but  their  shell  is  flattened,  nearly  triangular, 
inequilateral,  and  the  summits  are  nearly  vertical.    Several  small 
species  are  found  on  the  coasts  of  France,  the  shells  of  which  are 
very  pretty. 

5.  The  CYCLADES — Cyclas — have  the   same  hinge  and    are 
distinguished  from   the  preceding   by  the  rounded  form  of  the 
shell,  which  is  equilateral  (that  is,  the  two  halves  of  the  valve, 
situate  on  each  side  of  a  vertical  line  drawn  through  its  summit, 
are   alike),   and   striated   transversely.      One   species,    Tellina 
cornea,  is  common  on  the  coast  of  France.     The  genera  Cyrena 
and  Cyprina  belong  to  this  group. 

6.  The  Corbis  are  transversely  oblong  marine  shells,  which 
resemble  the  preceding  in  the  hinge;  their  external  surface  is 
very  regularly  marked  by  transverse  ribs,  crossed  by  diverging 
rays. 

7.  The  TELLING  (fig.  105)—  Tellina— closely  resemble  the 
Donaces;  but  they  have  the  middle  of  the  hinge  armed  with  one 
tooth  to  the  left,  and  two  to  the  right.     The   shell  is  slightly 
gaping.     Like  the  Donaces,  they  have  two  long  tubes  (fig.  105), 
which  can  be  entirely  concealed  within  the  shell  when  the  animal 
contracts.     Both  live  buried  in  the  sand  and  are  found  on  the 
coast  of  France. 


2.  What  are  the  principal  genera  belonging  to  the  family  of  Cardiacea  ? 

3.  What  are  the  characters  of  the  genus  Cardium  ? 

4.  What  are  the  characters  of  the  genus  Donax  ? 

5.  How  is  the  genus  Cy'clas  characterized  ?   (Cyclas,  from  the  GreeK, 
luMos,  a  circle.) 

6.  What  are  the  characters  of  the  genus  Corbis  ? 

7.  How  is  the  genus  Telli'na  characterized  ? 


VENUS.— MACTRA. 


85 


EXCAVATION 

OFTHEPALLIAL 

IMPRESSION 


Fig.  107. — VENUS. 


8.  The  VENUS 
(fig.  107)  is  re- 
cognised   by  the 

hinge,  the   ante-    /."I".™" 
rior    and*  poste- 
rior     plates     of  * 
which,       instead 
of    being    sepa- 
rated   from     the 
middle  tooth,  as  ^ 
in     the     Cardia, 
&c.,  are  approxi- 
mated in   a   sin- 
gle     group     be- 
neath   the   sum- 
mit.     The   shell 
is  generally  thick,   moderately  convex,  and  a  little  elongated 
The  species  of  this  genus  are  very  numerous. 

9.  The  genera  Petricola  and  Venerupis  (fig-  106)  resemble 
the  Venus  very  much,  and  have  obtained  their  names  from  living 
in  the  interior  of  stones  which  they  perforate. 

10.  The  MACTR^E  differ  from  other  cardiacese  in   having  an 
internal  ligament,  lodged  in  two  pits  in  the  hinge,  corresponding 

with  each  other  (fig.  108).  There 
are  some  large  species  on  our 
own  coast. 

11.  The  fifth  and  last  family  of 
testaceous  acephalse  or  INCLUSA, 
is  composed  of  mollusks  in  which 
the  mantle  is  only  open  at  its  an- 
terior extremity,  or  near  the  mid- 
dle, for  the  passage  of  the  foot, 
and  is  prolonged  posteriorly  in  a 
double  tube ;  in  other  parts  it  is 
completely  closed  (fig.  109). 
The  shell  is  always  gaping  at  the 


Fig.  108. MACTRA. 


Explanation  of  Fig.  107. — Cytherea,  or  Venus ; — s.  the  summit  or  beak  ; — 
I.  the  lunule  ; — p.  pit ; — A.  anterior,  and  P.  posterior  extremity  of  the  shell. 


8.  What  are  the  characters  of  the  genus  Venus  ? 

9.  From  what  circumstance  do  the  genera  Petrico'la  and  Venerupis  ob- 
tain their  names  ?     (Petricola,  from  the  Latin,  petra,  a  stone,  and  coZo,  I 
inhabit. — Venerupis,  Latin,  Venus', and  rupes,  a  rock.) 

10.  How    is   the   genus    Mac'tra    characterized  ?      (Mactra,    Latin,   a 
trough.) 

11.  What  are  the  general  characters  of  the  family  of  Inclusa  ?    (Inclusa, 
Latin,  enclosed.) 


86  LUTRARIA.— MYA.— BYSSOMIA.— HYATELLA.— SOLEN. 

extremities,  and  most  of  these  animals  live  buried  in  the 
sand  or  mud  .;  sometimes  they  excavate  holes  in  stones  or  wood. 
They  are  divide^into  Mya,  Lutraria,  Anatina,  Glycymera, 
Solemya,  Byssomia,  Hyatella,  Solen,  Psammobia,  Pholas,  Tere- 
do, Fistulana,  &c. 

12.  The  LUTRARI^E  closely  resemble  the  Mactrse ;  but  their 
hinge  is  unprovided  with  lateral  lamina?,  and  their  valves  are  very 
gaping,  particularly  behind,  through  which  passes  the  thick  fleshy 
cylinder  formed  by  their  double  tube.     A  large  species  is  found 
in  the  sand,  at  the  mouths  of  several  rivers  in  France. 

13.  In  the  Myse  there  is  a  projecting  plate  in  one  of  the  valves 
and  a  pit  in  the  other,  joined  by  a  ligament ;  the  ANATIN^E  have 
a  small  plate  in  each  valve,  giving  attachment   to  a   ligament  ; 
and  the  SOLEMYA  and  GLYCYMER^E  differ  from  the  MYJE  in  their 
external  ligament. 

14.  The  BYSSOMIJE,  in  place  of  living  in  the  sand  like  the 
preceding,  penetrate  stones  and  corals, .and  attach   themselves  to 
them  by  the  aid  of  a  byssus.     Their  shell  is  oblong,  without  a 
distinct  tooth,  and  gaping  about  the  middle  of  the  inferior  edge, 
for  the  passage  of  the  foot. 

15.  The  HYATELL.E  have  nearly  the  same  general  form;  but 
the  tooth  of  the  hinge  is  more  marked. 


Fig.  109. — SOLEN. 

16.  The  SOLENS,  commonly  called  razor  shells,  knife  handles 
(fig.  109),  from  the  cylindrical   and  elongated    form  of  their 

Explanation  of  Fig.  109. — c.  the  shell ; — a.  the  anterior  extremity  of  the 
mantle ; — p.  the  foot ; — t.  the  tentacles. 


12.  How  is  the  genus  Lutra'ria  characterized  ? 

13.  What  are  the  characters  of  the  genus  Mya  ? 

14.  What  are  the  characters  of  the  genus  Bysso'mia  ? 

15.  How  is  the  genus  Hyate'lla  characterized  ? 

16.  What  are  the  characters  of  the  genus  Solen  ? 


PHOLAS.— TEREDO.  87 

shell,  have  the  hinge  furnished  with  an  external  ligament,  and 
armed  on  each  side  with  two  or  three  projecting  and  very  de- 
cided teeth.  Their  foot  is  conical  and  is  pushed  out  at  the  anterior 
extremity  of  the  sheJL  They  live  in  the  sand,  and  bury  them- 
selves with  great  rapidity  by  the  motions  of  their  foot. 

17.  The  PHOLADES  are  distinguishable  from  all  the  preceding 
by  one  or  more  calcareous  pieces,  situate  between  the  two  valves 
of  the  shell,  near  the  hinge.     The  valves,  which  are  broad  and 
convex  anteriorly,  are  elongated  on  the  opposite  side,  and  leave 
betwixt  them  a  great  oblique  opening  at  each  end  ;  their  hinge 
resembles  that  of  the  Myse ;  their  double  tube  is  not  retractile 
and  may  be  very  much  elongated.    -  These  animals  inhabit  tubes 
or  long  cells,  which  they  excavate,  either  in  the  mud,  or  stones 
or  wood.     There  are  large  species  on  the  coast  of  France,  in  the 
West  Indies,  and  on  the  coast  of  Peru. 

18.  The  TEREDINES,  or  ship  worms,  are  celebrated  for  the 
ravages   they  commit   by  boring  into   ships'  bottoms,   piles  of 
dikes,    bridges,  &c.     These  are  mollusks    with  a 

very  elongated  and  almost  vermiform  body,  which 
is  enveloped  in  a  tubular  mantle,  open  at  the 
anterior  and  inferior  part  for  the  passage  of  the 
foot ;  it  is  provided  posteriorly  with  two  very  short, 
distinct  tubes,  and  its  base  is  furnished  on  each  side 
with  a  movable  stony  plate ;  the  shell  is  composed 
of  two  rhomboidal  valves,  but  is  very  small,  and 
covers  only  a  very  small  portion  of  the  mantle.  It 
seems  that  the  animal,  by  moving  the  extremity 
of  its  shell  like  an  auger,  excavates,  in  submerged 
wood,  the  hole  which  serves  as  its  abode,  and,  as  it 
advances  or  buries  itself  deeper,  it  lines  the  exca- 
vation with  a  calcareous  matter,  so  that  in  a  short 
time  it  finds  itself  lodged  in  a  stony  tube,  which  at 
first  might  be  mistaken  for  a  second  shell.  It 
begins  its  attack  upon  wood  when  very  young ; 
hence  the  external  opening  of  its  gallery  is  very 
small,  but  it  digs  on  until  the  termination  of  its 
growth,  and  progressively  augments  the  size  of  its 
dwelling ;  the  two  tubes  which  occupy  the  posterior 
extremity  of  the  mantle  always  remain  near  the 
opening  of  the  gallery,  and  through  one  of  them  it  causes  the 
water  necessary  for  respiration  and  nutrition  to  enter,  for  it 


1 7  How  is  the  genus  Pholas  characterized  ?  (Pholas,  from  the  Greek, 
pholeos,  a  lurking-place.) 

18.  What  are  the  characters  of  the  genus  Teredo  ?  (Teredo,  Latin,  a 
chip-worm.) 


88        FISTULANA.— GASTROCH^ENA.— ASPERGILLUM. 

always  remains  in  its  hole,  with  the  mouth  down  and  the  anus 
above.  The  common  Teredo,  which  is  about  six  inches  long,  it 
is  said  was  brought  from  the  torrid  zone,  but  it  is  widely 
spread  in  the  seas  of  France,  and  infests  the  dikes  of  Holland 
to  such  an  extent  that  its  unperceived  ravages  have,  more  than 
once,  been  near  producing  terrible  inundations.  Vessels  have 
been  sunk  by  the  holes  bored  through  their  bottoms  by  these 
animals.  To  guard  against  such  accidents,  is  one  among  the 
reasons  why  ships'  bottoms  are  covered  under  water  by  thin 
sheets  of  copper. 

19.  The  FISTTJLAN.E  also  live  buried  in  submerged  wood  or 
other  analogous  substances,  and  also  line  the  interior  of  their 
hole  with  a  calcareous  mortar   which  constitutes  a  tube,  com- 
pletely closed  at  the  large  end,  having  more  or  less  resemblance 
to  a  bottle.     Like  the  Teredines,  they  have  externally  a  small 
bivalve  shell  and  two  plates,  which  may  be  regarded  as  analo- 
gous to  the  operculum  pieces  of  the  gasteropods.     They  inhabit 
the  Indian  Seas. 

20.  The  GASTROCH^EN^E  differ  very  little  from  the  preceding; 
their  shell,  which  is  unprovided  with  teeth,  is  very  gaping   in 
front,  and  their  double  tube,  which  can  be  retracted  entirely  with- 
in the  shell,  is  susceptible  of  great   elongation ;  they  excavate 
holes  in  stones  or  masses  of  madrepore,  and  often  line  these  holes 
with  calcareous  matter  which,  on  becoming  hard,  constitutes  a 
tube  similar  to  that  formed  by  the  Teredo  and  Fistulana. 

21.  We   also   place   in   this   division    the    CLAVIGELLA    and 
ASPERGILLUM,  which  also  construct   a  calcareous  tube;  in  the 
first,  one  of  the  valves  is  clasped  by  the  tube,  while  the  other 
remains  free  in  its  'interior ;  and  in  the  last,  the  tube  has,  at  its 
closed  extremity,  a  disk  perforated  by  a  great  many  little  tube- 
like  holes,  an  arrangement  which  has  obtained  for  it  the  name  of 
"  watering-pot  shell." 

CLASS  OF  BHACHIOPOD  MOLLUSKS. 

22.  These    mollusks    are   very   analogous     to    the   common 
acephalse ;    they   are   also    provided    with    a  two-lobed  mantle, 


19.  What  are  the  characters  of  the  genus  Fistulana?    (Fistulana,  from 
the  Latin,  fistula,  a  pipe.) 

20.  What  are  the  characters  of  the  genus  Gastrochana  ?    (Gastrochsena, 
from  the  Greek,  gaster,  helly,  and  chaino,  I  gape.) 

21.  What  are  the  characters  of  Clavigella  ?  (Clavigella,  from  the  Latin, 
clavis,  a  nail  or   spike.)     How  is  the  genus  Aspergillurn  distinguished  ? 
(Aspergillum,  Latin,  a  watering-pot.) 

22.  What   are  the  characters   of  Brachiopod   mollusks  ?    (Brachiopod, 
pronounced  brak-e-opod,  from  the  Greek,  brachion,  an  arm,  and  jpows,  foot.) 


LINGULA TEREBRATULA. 


Fig.  Ul. 

TEREBRATULA. 


and  a  bivalve  shell ;  they  have  no  foot,  but 
in  place  of  it,  two  fleshy  arms  furnished 
with  filaments,  and  susceptible  of  being  un- 
folded externally,  or  drawn  within  the  shell 
by  folding  spirally  (Jig.  Ill,  a);  their 
branchia?  are  not  distinct  from  the  mantle, 
and  the  mass  formed  by  their  viscera  is  very 
small.  They  are  unprovided  with  organs  of 
locomotion,  and  live  attached  to  submarine 
bodies. 

The  principal  genera  composing  this 
group,  are  the  Lingula,  Terebratula,  and 
Orbicula. 

23.  The  LHNGUL.E  are  provided  with  a  long  fleshy  peduncle, 
one  extremity  of  which  is  generally  attached  to  the  rocks  these 
animals  ordinarily  inhabit,  and  the  other  is  furnished  with  two 
oblong,  flattened  valves.  Their  arms,  which  are  inserted  in  the 
sides  of  the  mouth,  are  very  long ;  and  the  branchial  vessels 
are  distributed  on  the  internal  face  of  the  mantle,  and  there  form 
on  each  side  a  series  of  small  parallel  folds.  They  are  found  in 
the  Asiatic  Seas. 

24.  The  TEREBRATULJE  have  two 
unequal  valves  joined  by  a  hinge, 
and  one  of  them  (fig.  112)  has  a 
hole  through  its  summit  for  the  pas- 
sage of  a  fleshy  peduncle,  by  means 
of  which  the  animal  attaches  itself. 
Their  branchiae  are  less  distinct  than 
in  the  Lingula?,  and  consist  simply  of 
a  vascular  net-work  spread  over  the 
internal  face  of  the  mantle ;  but 
their  muscular  system  is  more  de- 
veloped, and  there  is  found  in  the 
interior  of  the  shell  a  small  solid 
frame  (fig.  113),  the  structure  of 
which  is  sometimes  very  compli- 
cated ;  its  chief  uses  are  to  afford 
attachment  to  muscles,  and  to  as- 
sist in  separating  the  valves.  Some 
living  Terebratulse  are  found  in 
the  South  Seas ;  but  they  abound 
most  in  the  fossil  state;  and  are  Fig.  113. — TEREBRATULA. 

23.  What  arc  the  characters  of  the  genus  Lin'gula  ?   (Lingula,  Latin,  a 
latchet,  or  tongue  of  a  shoe.) 

24.  What  are  the  characters  of  the  Terebra'tulu  ?  (Terebratula.  from  the 
Latin  terebro,  I  bore.) 

8* 


Fig.  112. — TEREBRATULA. 


90 


BIPHORA. 


found  in  the  most  ancient  fossiliferous  strata  or  layers  of  the 
earth's  crust. 

25.  The  ORBICULJE  have  one  round,  conical  valve,  like  the 
shell  of  the  Patellae  (fig.  78,  p),  while  the  other   is  flat   and 
perforated  for  the  passage  of  a  very  small  peduncle  ;  the  confor- 
mation of  their  arms,  and  the  arrangement  of  their  branchial 
vessels,  very  closely  resemble  those  of  the  Terebratulse. 

CZiASS  OF  3XZOLLTJSC  A  TUNICATA,  OR  ACEPHALA 
WITHOUT  SHELLS. 

26.  The  acephalous  mollusks  without  shells,  which  have  also 
been  called  Tunicata,  differ  much  from  all  the  preceding  in  their 
general  form,  as  well  as  in  many  important  particulars  of  their 
organization.      Their  mantle   consists  sometimes   of   a   simple 
tube  open  at  both  ends,  and  sometimes  of  a  sack ;  their  branchiae 
present  different  forms,  but  always  very  little  developed,  and  arc 
never   divided  into  four  leaflets  or  laminae,  as  in  the  ordinary 
acephalse,    or    lamellibranch    testacea,    among   which   they  are 
placed  by  many  authors ;  they  have  neither  foot  nor  arm ;  and 
they  evidently  form  the  connecting  link  between  the  mollusks 
we  have  just  described  and  inferior  animals  which  are  ranged 
among  the  Polypi  in  the  branch  of  Zoophytes. 

27.  The  BIPHORJE  of  all  the  Tunicata  possess  the  most  com- 
plicated organization.     Their  mantle  is  tubular,  furnished  with 
transverse  muscular  bands,  and  enclosed  in  a  transparent,  car- 

/  on 


— p 


a--- 


br 

Fig.  114. BIPHORA. 

tilaginous  envelope ;  both  extremities  are  open,  and  the  posterior 
orifice  (p)  is  supplied  with  a  little  valve,  so  arranged  as  to 
admit  the  water,  but  not  to  allow  its  escape ;  the  mouth 

Explanation  of  Fig.  114. — a.  the  anterior  opening  of  the  mantle; — b.  the 
mouth  ;— /.  the  liver,  &c. ;— an.  the  anus  ; — br.  the  branchiae  ;— p.  posterior 
opening  of  the  mantle. 

25.  What  are  the  characters  of  the  genus  Orbicula  ? 

26.  What  are  the  general  characters  of  the  class  of  Tunicata  ? 

27.  What  are  the  characters  of  the  genus  Biphora? 


ASCIDIA  AGGREGATA.  91 

is  placed  in  the  tube  formed  by  the  mantle  towards  its  anterior 
extremity ;  and  the  heart,  liver,  and  other  viscera,  are  united 
into  a  small  mass  near  this  opening ;  the  anus  is  situate  far  be- 
hind, and  the  only  branchia,  which  is  formed  of  a  membrane 
transversely  plaited,  extends  obliquely  from  the  superior  to  the 
inferior  parietes  of  the  pallial  cavity ;  the  water  which  traverses 
this  tube,  consequently  laves  the  respiratory  apparatus,  and  the 
animal  moves  by  forcibly  expelling  it  from  the  side  of  the  mouth  : 
hence,  we  see  it  must  necessarily  swim  backwards.  When 
full  grown,  these  mollusks  are  free  ;  but  at  birth  they  are  fre- 
quently united  to  each  other,  forming  a  long  chain,  and  swim 
in  this  manner  for  a  long  time;  it  seems  that  the  individuals 
thus  united,  after  becoming  free  or  separated,  produce  young, 
which  are  not  joined  together  in  a  chain  as  just  described,  and 
differ  from  tfrem  in  form,  and  that  the  young  arising  from  the 
last  are  united  and  similar  to  the  first ;  so  that  in  these  singu- 
lar animals  there  is  the  most  remarkable  alternation,  the  same 
form  and  the  same  mode  of  existence  not  being  transmitted  from 
one  generation  to  the  other,  but  constantly  returning  to  the 
second  generation. 

The  Biphorse '  are  found  in  the  Mediterranean,  and  in  the 
warmer  regions  of  the  ocean  ;  they  frequently  emit  a  phosphoric 
light. 

28.  The  simple  ASCIDIA  cannot  move  like  the  Biphorse,  but 
live  attached  to  rocks ;  their  mantle  is  in  the  form  of  a  sack, 
with  two  orifices,  and  the  interior  of  this  cavity  is   lined  with  a 
net-work  composed  of  the  branchial  vessels ;  the  mouth  and  the 
little  bag  or  sack  containing  the  viscera,  are  attached  to  the  bot- 
tom of  the  great  branchial  cavity,  and  the  anus  is  found  near  one 
of  its  openings. 

29.  Other  Tunicata,  closely  resembling  the  preceding  in  their 
organization,  live  united  in  a  common  mass,  and  for  this  reason 
they  are  designated  under  the  name  of  ASCIDIA  COMPOSITA  or 
AGGREGATA.     A   gelatinous   or   cartilaginous  tissue   encloses  a 
great  number  of  these  little  beings,  the  surface  of  which  presents 
a  multitude  of  six-pointed  stars  formed  by  their  openings ;  their 
propagation  seems  to  be  effected  in  two  ways  ;  sometimes  the 
mass   grows    by  the  development  of  reproductive  buds  in  this 
common  tissue,  sometimes  the  young  formed   in  an  ovary  are 
expelled  externally,  and  swim  about  free  or  separately  for  some 
time,  until  they  become  attached  to  some  submarine  body,  where 
they  establish  a  new  colony. 

28.  What  are  the  characters  of  the  genus  Ascidia?     (Ascidia,  from  the 
Greek,  askos,  a  bottle  or  pouch.) 

29.  What  is  meant  by  the  Aggregata?     (Aggregata;  Latin,  gathered 
together.) 


92  BOTRYLLUS — PYROSOMA. 

30.  We  give  the  name  of  BOTRYLLUS  to  small  aggregated 
Tunicata  of  an  oval  form,  which  differ  little  from  the  preceding, 
except  their  branchial  sack  is  open  at  both  extremities,  and  the 
anal  orifice  terminates  in  a  central  cavity,  around  which  ten  or 
twelve  of  these  mollusks  are  grouped  like  the  rays  of  a  star. 


Fig.  115. — PYROSOMA. 

31.  The  PYROSOMA  unite  in  great  numbers,  forming  a  large 
hollow  cylinder,  open  at  one  end  and  closed  at  the  other,  which 
swims  in  the  ocean  by  the  alternate  contraction  and  dilatation  of 
the  animals  that  compose  it.  In  their  individual  organization  they 
are  similar  to  the  preceding. 

OF  THE  PARTS  OF  SHELLS. 

We  have  now  brought  our  history  of  the  Mollusca  to  a  close  ; 
but  with  the  view  of  imparting  clearer  notions  on  the  subject  of 
Conchology,  or  History  of  Shells,  we  shall  add  here  a  few 
words  in  relation  to  the  parts  of  shells.  It  is  absolutely  neces- 
sary to  understand  these  parts,  before  we  can  comprehend  the 
descriptions  given  by  conchologists,  or  be  able  to  describe  shells 
in  such  a  way  as  conchologists  can  recognise  them. 

The  most  simple  farm  of  a  shell  is  the  cone  (fg-  70,  page 
57).  The  apex  of  the  cone  is  oblique  and  excentric.  In  the 
Limpets  (Patella),  Argonaut,  and  Nautilus,  the  apex  is  directed 
towards  the  head,  but  in  most  other  mollusks,  towards  the  oppo- 
site extremity  of  the  body. 

A  shell  may  consist  of  one  piece,  as  in  the  inopercular 
univalves — that  is,  univalves  without  an  operculum  or  door. 

A  shell  may  consist  of  two  pieces,  as  in  the  opercular 
univalves  (univalves  with  an  operculum),  and  in  most  bivalves. 

A  shell  may  consist  of  three  pieces,  as  in  the  Terebratula 
(Jigs.  112  and  113,  page  89). 

A  shell  may  consist  of  four  or  more  pieces,  as  in  some  of  the 
Pholades. 

A  shell  may  consist  of  many  pieces,  in  which  case  it  consti- 
tutes a  multivalve,  as  the  Chiton  (fg.  79). 

30.  What  are   the  characters  of  the   Botryllus.      (Botryllus,  from  the 
Greek,  botrus,  a  bunch  of  grapes.) 

31.  What  are  the  characters  of  the  genus  Pyrosoma  ?     (Pyrosoma,  from 
the  Greek,  pur,  fire,  and  sower,  body — fire-bodies  ;  so  called  from  possessing 
the  faculty  of  emitting  light.) 


PARTS  OF  UNIVALVE  SHELLS.  93 

The  univalve  shells  are  much  more  numerous  than  any  others, 
both  in  genera  and  species ;  and  it  requires  a  considerable  de- 
gree of  attention  to  discriminate  many  of  the  species,  as  they 
run  into  each  other  so  much. 

In  the  examination  of  univalve  shells,  the  general  outline  or 
contour  of  the  whole  shell  is  the  first  particular  to  be  attended 
to,  as  this  leads  to  those  distinctions  necessary  in  the  definition 
of  simple,  spiral,  or  turbinated  shells,  or  more  strictly,  accord- 
ing to  the  Linnean  method  of  discrimination,  univalves  with  a 
regular  spire,  and  those  without  a  regular  spire.  Univalve 
shells  are  classified  principally  from  the  shape  of  the  aperture, 
taken  in  conjunction  with  the  general  shape  of  the  shell ;  from 
the  spire  being  lengthened  or  depressed,  being  with  or  without  a 
canal,  the  length  of  the  beak  and  its  direction,  together  with 
the  particular  form  of  the  outer  or  external  lip  :  the  colour  of 
shells  only  serves  as  a  specific  distinction,  and,  even  in  this 
respect,  cannot  in  all  cases  be  depended  upon,  although,  in 
others,  it  is  an  unvarying  test.  The  particular  manner  in  which 
the  spots  are  disposed,  frequently  characterizes  species. 

Apex,  is  the  summit,  tip,  or  highest  part  of  a  shell  (fig*  116). 

Base,  is  the  opposite  extremity  from  the  apex  (Jig.  116).  In 
shells  with  a  beak  or  rostrum  (as  the  Murex,^-.  64),  it  implies 
the  tip  of  such  beak ;  in  shells  without  a  beak  it  is  understood 
to  be  the  lower  part,  as  before  mentioned,  opposite  the  apex.  In 
the  Patella,  and  some  others,  the  base  of  the  shell  is  that  part  on 
which  it  rests  when  it  is  laid  on  its  mouth  ;  in  the  Teredo,  and 
similar  shells,  it  is  the  wider  end. 

Body  of  the  shell,  is  the  first  or  lower  whorl  of  the  spire,  in 
which  the  aperture  is  situated ;  this  whorl  is  generally  longer 
than  the  others  (Jig.  18). 

Front  of  the  shell,  is  that  side  where  the  aperture  is  situated. 

Back  of  the  shell,  is  the  opposite  side  to  that  in  which  the  aper 
ture  is  placed. 

The  venter  or  belly,  is  the  most  prominent  part  of  the  lower 
whorl  or  body,  generally  situated  in  the  vicinity  of  the  lip  over 
the  aperture,  and  formed  by  the  convexity  of  the  aperture.  In 
general  this  term  is  only  made  use  of  in  describing  shells 
whose  body  is  large  in  proportion  to  the  size  of  the  spire  ( fas. 
52  and  59). 

Sides  of  a  shell,  are  the  extreme  edges  of  the  shell,  when 
viewed  either  in  front  or  from  the  back.  The  right  side  is  the 
one  next  the  observer's  left  hand,  when  the  shell  is  viewed  in 
front ;  arid  the  side  with  the  aperture  in  it,  is  the  left  side. 

The  conical  univalve  shell  is  generally  spirally  convoluted  ; 
sometimes,  as  in  the  nautilus  (Jigs.  15  and  16),  in  the  same 


04 


PARTS  OF  UNIVALVE  SHELLS. 


plane,  but  more  usually  in  an  oblique  direction.     As  a  general 
rule,  the  spiral  univalve,  if  viewed  in 
Base.  the    position   in  which   its    inhabitant 

would  carry  it,  if  moving  forwards 
from  the  observer,  is  twisted,  from  the 
apex  downwards,  from  left  to  right, 
the  spire  being  directed  obliquely  to- 
wards the  right.  The  annexed  figure 
(Jig.  116)  shows  the  involutions  or 
whorls  of  the  spire  of  the  Pleurotoma. 
In  some  genera,  for  example,  Clausilia 
(from  the  Latin,  clausus,  shut,  jig.  25, 
page  40)  and  Physa  (from  the  Greek, 
phusa,  a  bubble,  fig,  30,  page  42),  the 
shell  is  twisted  in  an  opposite  direc- 
tion :  such  shells  are  called  "  per- 
verse," or  "  sinistral." 

The  aperture  or  mouth,  is  that  part 
of  the  lower  whorl  or  body  through 
which  the  animal  protrudes  itself. 
This  is  one  of  the  principal  means  of 
distinguishing  the  genera  of  univalve 
shells,  and  it  varies  much  in  its  form; 
some  apertures  are  rounded  (figs.  43 
and  46);  others  semilunar  (fig.  55); 
others  angular  (fig.  37),  &c.  Some 
apertures  have  a  canal  at  their  base 
(figs.  63  and  11 6),  and  others  are  with- 
out it  (fig.  51).  In  various  genera, 
the  aperture  extends  the  whole  length 
of  the  shell,  as  in  Ovula  (fig.  68), 
Cyprsea,  and  some  of  the  Cones  with 
depressed  spires  (fig.  70).  In  several  individuals,  the  aperture 
is  either  entirely  open,  or  closed  by  an  operculum  or  door,  which 
is  usually  affixed  to  the  foot  of  the  animal. 

When  without  a  notch  or  canal,  the  aperture  is  said  to  be 
entire  (fig.  51).  The  aperture  has  two  lips  or  borders;  the 
internal  lip,  or  border,  is  on  the  side  of  the  aperture,  formed  by 
the  columella,  and  the  external,  or  outer  lip,  or  border,  is  oppo- 
site, as  in  the  Pleurotoma  (fig.  116) ;  the  letter  b.  indicates  the 
pallial  notch  ;  n.  notch  of  the  syphon. 

Canal,  or  gutter  (fig.  116),  is  the  space  or  hollow,  formed  by 
the  prolongation  of  the  two  lips  of  the  aperture.  Some  shells 
have  two  canals,  one  situated  at  the  point  where  the  outer  lip  and 
body  join. 


Apex. 
Fig.  116. PLEUROTOMA. 


PARTS  OF  UNIVALVE  SHELLS.          95 

Beak  or  rostrum,  is  that  lengthened  process  in  which  the 
canal  is  situate.  This  process  is  not  so  conspicuous  in  some  of 
the  species  of  Voluta,  but  is  more  marked  in  the  genera  Murex, 
Fusus,  &c. 

The  columella  or  pillar,  is  that  process  which  runs  through 
the  centre  of  the  shell  in  the  inside,  from  the  base  to  the  apex, 
and  around  which  the  whorls  or  wreaths  of  the  spire  are  wound 
(fig.  19,  page  34).  When  the  columella  is  marked  by  ridges 
or  folds,  as  in  Auricula  (Jig.  31)  and  Oliva  (Jig.  67),  it  is  said 
to  be  plicated  or  plaited,  but  when  it  is  smooth,  as  in  Jig.  116, 
it  is  simple. 

Pillar  lip,  is  a  continuation  of  the  glassy  process  with  which 
the  aperture  is  lined,  and  expanded  on  the  columella  (figs.  58 
and  66).  It  is  also  called  the  inner  or  internal  lip  (fig.  116). 

The  outer  lip,  or  external  border,  is  the  expansion  or  con- 
tinuation of  the  body  of  the  shell,  on  the  left  margin  of  the 
aperture,  and  is  also  lined  with  the  glossy  process  of  the  aperture 

(fig-  H6). 

Spire  consists  of  all  the  whorls  of  the  shell  except  the  lower 
one,  which,  as  before  observed,  is  termed  the  body  of  the  shell. 
This  spire  is  a  prominent  feature  of  the  univalve ;  and  upon  its 
being  elevated,  depressed,  &c.,  depends  much  of  the  generic  and 
specific  definition  of  these  shells. 

It  is  a  remarkable  circumstance,  that  many  of  the  young 
shells  have  not  the  same  number  of  wreaths  as  the  adults  ; 
from  which  it  would  appear,  that  the  part  of  the  animal  nearest 
the  apex  never  increases  in  size.  The  number  of  wreaths 
cannot,  at  all  times,  be  depended  upon.  A  full-grown  shell 
may,  however,  be  known  from  the  outer  lip,  whicl^has  generally 
an  unfinished  appearance  in  young  shells.  Indeed,  in  all  the 
land  and  fresh-water  shells,  it  is  a  distinct  criterion,  as  they  are 
never  complete  in  the  form  of  the  outer  lip,  till  full-grown. 

Whorl  is  one  of  the  wreaths  or  volutions  of  the  shell  (fig. 
116). 

Depressed  spire  is  when  the  spire  is  very  flat,  as  in  the  shells 
of  the  genus  Planorbis  (fig.  29,  page  42). 

Involuted  spire,  is  where  the  spire  is  concealed  in  the  inside 
of  the  first  whorl  or  body,  as  in  some  of  the  Nautili,  Cvprsese, 
Ovulie,  &c.  (fig.  68). 

Suture  of  the  spire,  or  whorls,  is  a  fine  spiral  line  or  seam, 
formed  by  the  joining  together  of  the  whorls ;  it  is  sometimes 
crenulated,  undulated  (waved),  or  sulcated  (grooved),  and  not 
unfrequently  elevated  or  projecting  (fig.  116). 

Reversed,  or  heterostrophe  spire,  is  when  the  volutions  of  the 
spire  revolve  in  the  same  manner  as  the  common  corkscrew,  or 


96  PARTS  OF  BIVALVE  SHELLS. 

when  the  aperture  is  placed  downwards,  the  nature  of  the  spire 
runs  upwards  from  the  right  hand  to  the  left  (Jig-  25). 

Chambers  are  the  cavities,  divided  by  partitions  at  regular  or 
irregular  intervals,  as  in  the  Nautilus  (Jig.  15,  page  30). 

Umbilicus  is  a  circular  perforation  in  the  base  of  the  lower 
whorl  or  body.  (See  page  38). 

Sub-nmbilicated  shells,  are  those  which  have  the  umbilicus 
covered,  in  a  greater  or  less  degree,  by  a  thin  process  ;  which, 
in  some,  almost  entirely  closes  the  aperture  or  mouth.  This 
character  is  most  commonly  to  be  met  with  among  species  of 
Buccinum  and  Murex. 

Umbilical  fissure,  is  a  groove  extending  from  the  umbilicus 
(fig.  US). 

Shells  which  have  no  umbilicus  are  termed  imperforate. 

Siphunculus  (little  syphon)  is  that  small  round  perforation 
which  forms  a  communication  between  the  chambers  in  the 
Nautilus,  and  penetrates  through  the  whole  spire  of  the  shell 
(Jigs.  15  and  16). 

Varices  are  transverse  ribs  which  cross  the  whorls  of  shells 
in  some  species  of  Buccinum,  Murex,  &c.  Varices  are  formed 
by  the  periodical  growth  of  the  shells,  these  being  the  margin  of 
the  outer  lip,  to  which  the  animal  has  attached  its  periodical 
enlargements  (Jig-  46).  In  some  species  they  have  more  the 
form  of  sutures  than  ribs ;  this  is  owing  to  the  margin  of  the 
outer  lip  being  but  slightly  developed. 

Ribs  are  those  longitudinal  and  transverse  protuberances 
which  are  in  many  of  the  univalve  shells  (fig.  46). 

Teeth  of  univalves,  according  to  Colonel  Montagu,  are  not 
properly  tootrnshaped  protuberances,  but  are  fine  white  Iamina3 
or  ridges,  running  spirally  backwards,  in  a  direction  parallel  to 
each  other  ;  those  on  the  exterior  lip  may,  in  most  instances,  be 
traced  through  the  outside  of  the  shell,  and  are  nearly  alike  in 
length  (figs.  24,  25  and  42). 

Epidermis  is  a  skin,  or  cuticle,  covering  the  exterior  surface 
of  many  shells,  destined  by  nature  to  protect  their  surface  from 
being  injured. 

True  bivalve  shells  are  peculiar  to  the  acephalous  mollusca; 
and  their  presence  is  constant,  although  they  are  in  a  few 
instances  too  small  to  cover  the  whole  body,  and  in  the  ship- 
borers  (Teredo)  exist  only  as  small  instruments,  limited  to  the 
function  of  excavating  the  burrows  inhabited  by  these  mollusks. 
But  all  the  species,  in  which  the  bivalve  shell  is  inadequate  to 
the  protection  of  the  whole  body,  derive  extrinsic  defence  by 
burrowing  in  sand,  or  stone,  or  wood ;  and  they  also  commonly 
line  their  burrows  with  a  layer  of  smooth  and  compact  cal- 


PARTS  OF  BIVALVE  SHELLS.  97 

careous  matter,  forming  a  tube.  This  calcareous  tube,  in  some 
cases,  is  of  considerable  size  and  thickness.  In  the  Clavigella 
one  valve,  and  in  the  Aspergillum  both  valves,  are  soldered  to 
this  tube,  which,  in  the  latter,  presents  a  peculiar  modification 
of  its  exposed  extremity,  which  resembles  the  end  of  the  spout 
of  a  watering-pot.  No  two  shells  can  present  a  greater  con- 
trast than  do  those  of  the  Placuna  and  Aspergillvm ;  yet  the 
organization  of  their  respective  constructors  is  essentially  the 
same.  In  a  classification  of  shells,  the  calcareous  tubes  of  the 
Dentalium,  Serpula,  Aspergillum,  Vermetus,  &c.,  would  be 
associated  in  the  same  general  group :  but  it  needs  only  to 
observe  how  these  products  of  animals,  belonging  not  only  to 
different  classes,  but  to  distinct  primary  divisions  of  the  animal 
kingdom,  are  arranged  in  the  cabinets  of  collectors,  to  be  con- 
vinced that  Conchology  as  a  classificatory  science,  apart  from 
Malacology  (the  science  of  mollusks),  no  longer  exists. 

With  regard  to  the  structure  and  physiological  relations  of 
bivalve  shells,  it  may  be  observed,  first,  that  in  all  acephalous 
mollusks  which  breathe  by  distinct  iamellaled  gills  (branchiae), 
— Lamellibranckiata, — one  valve  corresponds  to  the  left,  the 
other  to  the  right  side  of  the  animal ;  but  in  the  brachiopodous 
bivalves,  one  valve  is  applied  to  the  ventral,  and  the  other  to  the 
dorsal  aspect  of  the  animal. 

In  all  the  lamellibranch  bivalves  which  are  free,  the  two 
valves  are  symmetrical,  and  the  shell  is  termed  equivalve  ;  in 
all  those  which  adhere  by  one  of  their  valves  to  foreign  bodies, 
this  valve  is  deeper  and  larger  than  the  unattached  valve ;  such 
shells  are  termed  inequivalve.  Of  those  acephalans  which  are 
attached  to  foreign  bodies  by  means  of  a  byssus,  some,  as  the 
Tridacna  (fig.  103),  are  equivalve,  and  both  valves  are 
notched,  to  form  the  hole  for  the  passage  of  the  byssus ;  while 
others,  as  the  Pecten  (fig.  91),  and  Avicula  (fig.  95),  are 
inequivalve,  the  byssus  passing  through  a  groove  in  the  right 
valve. 

If  the  shell  of  the  common  cockle  be  examined,  each  valve 
will  be  seen  to  be  produced  into  a  conical  prominence  bent 
towards,  and  nearly  meeting  at,  that  part  by  which  the  valves 
are  joined  together.  These  prominences  are  termed  the  umbones> 
or  sometimes  beaks.  The  apex  of  the  umbo  corresponds  to 
the  apex  of  the  univalve  shell,  and  is  the  point  at  which  the 
development  of  the  bivalve  commences.  When  the  apex  is 
directed  in  the  transverse  plane  of  the  shell,  and  so  placed, 
that  a  division  of  the  shell  in  that  plane  through  the  apices 
shall  divide  the  valve  into  two  equal  parts*  the  shell  is  termed 
equilateral;  of  this  form  the  Pecten  (fig.  91)  is  au  example, 
9 


98  PARTS  OF  BIVALVE  SHELLS. 

When  upon  a  similar  division,  a  slight  difference  is  observed 
in  the  two  valves,  the  shell  is  termed  subequilateral ;  but 
where  the  difference  is  well  marked,  it  is  an  inequilateral  bivalve 
(Jig.  117).  When  the  apex  is  bent,  as  is  commonly  the 
case,  out  of  the  transverse  plane,  it  is  always  directed  more  or 
less  towards  the  anterior  part  of  the  shell ;  if  such  a  bivalve 
shell  as  the  Cytherea,  or  Isocardia,  be  held  before  the  observer, 
with  the  umbones  directed  forward,  and  the  hinge  above, — in  the 
position,  in  fact,  in  which  the  living  animal  would  place  itself 
if  it  were  creeping  forwards  from  the  observer, — the  right  valve 
will  of  course  correspond  with  the  right  hand  of  the  observer,  and 
the  left  with  the  left. 


Superior  or  dorsal  border. 


*•• 


Fig.  117. — LEFT  VALVE  OF  A  CYTHEREA. 

The  annexed  figure  (117)  represents  the  left  valve  of  a. 
Cytherea, — the  common  clam  belongs  to  this  group,  and  would 
answer  our  purpose  as  well.  You  see  that  the  superior  or 
dorsal  margin  is  on  the  side  where  the  hinge  is  placed,  and  the 
ventral  or  inferior  border  opposite  to  it;  A,  is  the  anterior 
margin  or  slope ;  P,  the  posterior  margin  or  slope ;  the  umbo 
is  marked  "  BEAK,"  and  s,  points  to  the  summit  or  apex  of  the 
beak ;  /,  shows  the  situation  of  the  Ivnule.  Now,  if  a  bivalve 
in  which  the  apices  have  a  spiral  twist,  as  in  the  Isocardia 
(fig.  104),  be  placed  in  the  above  position,  and  compared  with 
the  univalve  shell  of  the  Purpvra,  it  will  be  seen  that  the  left 
valve  corresponds  with  the  ordinary  or  dextral  spiral  univalve, 
and  the  right  valve  to  the  perverse  or  sinistral  univalve. 

When  the  circumference  or  margin  of  one  valve  fits  exactly, 
at  every  part,  that  of  its  fellow,  it  is  said  to  be  "  regular"  or 
".entire ;"  but  if  it  be  notched  at  any  part,  so  as  not  to  come 


PARTS  OF  BIVALVE  SHELLS. 


in  contact  with  the  corresponding  part  of  the  opposite  valve,  it  is 
"  irregular,"  or  emarginate. 

Besides   the    parts    mentioned,  A 

we  shall  find  in  most  cases,  an- 
terior to  the  apices  of  the  beaks, 
a  depression  of  variable  extent 
and  depth.  This  is  the  lunule 
(fig.  118,  1)  :  it  may  be  cordi- 
form,  or  crescentic,  lanceolate 
(oblong,  and  gradually  tapering 
towards  each  extremity),  oval, 
deep,  superficial,  &c.  Behind 
the  beaks  is  another  depression, 
longer  and  narrower  than  the 
lunule,  and  which  is  called  the 
fissure  (f),  and  its  margins 
are  named  lips  of  the  fissure 
( I/).  Behind  the  fissure  there  is 
sometimes  a  small  depression 
called  the  suture  (s).  The 
general  more  or  less  convex 
surface  of  each  valve  is  called 
the  "venter,"  or  belly,  which 
terminates  in  the  limb,  circum- 
ference or  margin.  In  the  figure  (118),  the  letters  designate 
parts,  as  follows :  A,  anterior  slope ;  P,  posterior  slope ;  L,  left 
valve  ;  JR,  right  valve  ;  Z,  lunule ;  /.  fissure  ;  //*,  lips  of  the  fis- 
sure ,*  s,  suture  ;  lig,  ligament ;  ny,  the  nymphse. 


•ny 


Fig.  118. — CYTHEREA. 


•       /LIGAMENT-.      \ 
'  .MWHAEv  \      \ 


gCARUTV  .••'OF  THE  PALLIAL 
IMPRESSION 


Fig.  119. RIGHT   VALVE   OF    A   CYTHEREA. 

The  most  important  part  of  the  margin  is  that  which  is 


100  PARTS  OF  BIVALVE  SHELLS. 

modified  to  form  the  joint  or  hinge  upon  which  the  two  valves 
open  and  shut.  This  part  is  called  the  "  cardinal  edge"  (jig. 
119),  and  generally  presents  certain  prominences  and  depressions  ; 
the  projections  of  one  valve  interlocking  with  the  depressions  of 
the  other.  The  projections,  or  "  teeth,"  together  with  the  cavi- 
ties, or  "  cardinal  pits"  (p),  are  very  regular  in  their  formation 
in  each  genus  and  species  of  bivalve,  but  what  is  of  more  impor- 
tance is,  that  every  modification  in  the  structure  of  the  hinge  is 
generally  found  to  coincide  with  some  recognisable  and  more  or 
less  important  difference  in  the  organization  of  the  soft  parts ;  so 
that  conchologists  have  justly  attached  great  value  to  the  charac- 
ters derivable  from  the  hinge,  especially  for  the  purpose  of  gene- 
ric distinctions.  When  the  teeth  are  situate  beneath  the  apex  (s) 
or  centre  of  the  hinge,  they  are  called  cardinal,  or  primary  / 
when  they  are  removed  from  the  centre  of  the  hinge,  they  are 
named  lateral  teeth  ;  when  two  only  are  present,  one  is  called 
anterior,  the  other  posterior  ;  when  there  are  three,  they  are  dis- 
tinguished respectively  as  anterior,  median  or  middle,  and  pos- 
terior teeth ;  but  when  the  hinge  is  composed  of  a  great  number 
of  teeth,  it  is  said  to  be  "  serial,"  as  in  Area  (Jig.  97) ;  some 
hinges  have  no  visible  teeth,  and  are  termed  inarticulate. 

The  direct  medium  of  union  of  the  two  valves  is  a  dense  fasci- 
culus (bundle)  of  elastic  fibres,  generally  of  a  brown  colour,  called 
ligament,  or  elastic  ligament.  The  fibres  of  this  part  are  at- 
tached by  their  extremities  to  the  two  valves,  which,  in  most  cases, 
present  a  particular  depression  for  their  reception.  The  ligament 
is  always  so  long  as  to  prevent  the  actual  closing  of  the  valves, 
except  when  its  elasticity  is  overcome  by  a  certain  force,  as  by 
that  of  the  contraction  of  the  adductor  muscle  or  muscles  :  thus, 
the  inorganic  power  of  elasticity  is  made  the  direct  antagonist  of 
a  vital  and  muscular  contraction ;  and  as  the  open  or  expanded 
condition  of  the  bivalve  shell  is  that  which  the  exigences  of  the 
animal  most  constantly  require,  it  is  assigned  to  a  force  which 
can  act  without  ever  causing  fatigue,  while  the  occasional  or 
protective  action  of  forcibly  closing  the  valves,  is  due  to  an  ac- 
tion under  the  immediate  control  of  the  will  or  instinctive  sensa- 
tion. The  modifications  of  the  internal  surface  of  a  bivalve 
shell  are  caused  by  the  structure  of  the  animal  inhabiting  it : 
hence,  they  afford  the  characters  by  which  the  habits  of.  an  ex- 
tinct  genus  may  be  to  a  great  extent  determined. 

These  modifications  are  marked  on  the  last  figure. 

The  pallial  impression  shows  the  development  of  the  muscu- 
lar margin  of  the  mantle. 


GLOSSAKY. 


CONCHOLOGY. 


ABDO'MEN. — The  belly;  the  cavity 
which  contains  the  stomach,  liver, 
&c. 

ABDO'MINAL. — Belonging  or  relating 
to  the  belly. 

ACE'PHALA  (a-ke'f-ala.) —  From  the 
Greek,  a,  without,  and  kephale, 
head, — without  a  head.  The  Latin 
word  animalia,  animals,  is  under- 
stood ;  therefore,  acephala  means 
animals  without  a  head. 

ACE'PHALA  (a-ke'f-alay').— Latin.  Flu- 
ral  of  acephala. 

ACE'PHALOUS  (a-ke'f-alous).  —  Head- 
less ;  belonging  or  relating  to  ace- 
phalae. 

ACETA'BULIFE'RA. —  From  the  Latin, 
aceta'bulum,  a  little  cup,  and  fero, 
I  carry.  Applied  to  those  cephalo- 
pods  that  have  cups  or  suckers  on 
their  arms  or  tentacles. 

ACHATI'NA  (akate'na).  —  From  the 
Greek,  achates,  agate.  Name  of  a 
genus  of  terrestrial  gasteropods, 
sometimes  known  as  the  agate 
snails.  All  the  species  of  this 
genus  are  ovi'parous,  and  one,  the 
Achatina  zebra,  figured  on  page 
41,  lays  eggs  with  a  hard,  white 
shell  and  as  large  as  those  of  a 
sparrow. 

ADDU'CTOR  (muscle) — From  the  Latin, 
addu'co,  I  draw  towards.  The 
muscle  which  draws  the  valves 
of  a  bivalve  shell  towards  each 
other,  is  so  called. 

AD'NATE. — Adhering  or  growing  to- 
gether. 

AGGLU'TINANS. —  Latin.    Glueing;   a 

•     gasteropod  which  has  the  faculty 

of  causing  other  species,  or  parts 

of  shells,  to   adhere   to   it,   is  so 

named. 

AGGREGA'TA.— Latin.  Gathered  to- 
gether. 

AGGRE'STIS. — Latin.     Rural,  wild. 

AKE'RA. — From  the  Greek,  a,  with- 
9* 


out,  and  keras,  horn, — hornless. 
Name  of  certain  mollusks  that 
have  very  short  tentacles,  or  none 
at  all  (page  64). 

AKE'RA. — Plural  of  Akera. 

ALA'TED. — Winged. 

ALIMEN'TARY  (canal). — The  intestinal 
tube  is  so  called  because  it  is  the 
medium  through  which  food  is 
conveyed  into  the  body. 

ALU'CO.  —  Specific  name  of  a  shell 
(page  54). 

AM'BIENT. — 'Surrounding,  investing. 

AMBRE'TTE.  —  From  the  French, 
ambre,  amber ;  name  of  a  shell 
supposed  to  resemble  amber  (page 
41). 

AM'MON. — From  the  Greek,  ammos, 
sand.  Name  of  a  heathen  divinity 
whose  temple  was  in  the  sands  of 
the  desert. 

AM'MONITES. — Ammonites,  •  -vulgarly 
called  Snake  Stones,  are  fossil 
shells  found  in  the  strata  of  the 
secondary  formation,  varying  from 
the  size  of  a  bean  to  the  dimen- 
sions of  a  coach-wheel.  Their 
name  is  derived  from  their  resem- 
blance to  the  horns  on  the  statue 
of  Jupiter  Amtnon  (page  31). 

AMPULLA'RIA. — From  the  Latin,  am- 
pulla, a  bottle  or  jug ;  any  thing 
puffed  or  swelled  out. 

AMPULLA'RIA. — Plural  of  ampullaria. 

ANA'TIFA.  —  From  the  Latin,  anas, 
in  the  genitive  case,  anaiis,  a  duck, 
and  fero,  I  bear  ;  a  genus  of  bra- 
chiopod  mollusks.  It  was  for  a 
long  time  believed  that  certain 
ducks  were  derived  from  the 
metamorphosis  of  these  animals ; 
and  for  this  reason  they  were 
called  anatifa. 

ANATI'NA.— Name  of  bivalves  which 
resemble  the  Solens  (page  86). 

ANGIO'STOMA. — From  the  Greek,  ag 


102 


CONCI1GLOGY.— GLOSSARY. 


g.?ion,  i  vejjsely  an.d  stowa,  mouth 
(page  56). 

ANODO'NTA.  —  From  the  Greek,  a, 
without,  odos,  in  the  genitive,  odon- 
tos,  tooth — without  teeth.  Sys- 
tematic name  of  a  kind  of  mus- 
sel, the  shell  of  which  is  without 
teeth. 

ANODO'NTVE. — Plural  of  Anodonta. 

ANO'MIA. — Greek,  a,  without,  and 
nomos,  law.  Systematic  name  of 
certain  mollusks  (page  74). 

ANOMI^E. — Plural  of  Anomia. 

A'NUS. — Latin.  The  inferior  opening 
of  the  rectum  for  the  passage  of 
excrement. 

AOR'TA.— The  principal  artery  of  the 
body  is  so  called. 

AOR'TIC. — Belonging  or  relating  to 
the  aorta. 

APERTURE. — The  mouth  or  opening 
of  the  shell. 

APEX. — The  tip  or  point  of  the  spire 
of  a  shell. 

ArLY'siA.^-From  the  Greek,  aplusia, 
uncleannese;  that  which  cannot 
clean  itself.  Systematic  name  of 
Sea-hares,  to  which  the  ancients 
attributed  many  fabulous  proper- 
ties. 

APLY'SI^E. — Plural  of  Aplysia. 

APPARATUS, — Latin ;  formed  from  dd, 
for,  and  parare,  to  prepare.  A  col- 
lection of  organs  or  instruments 
for  any  operation  whatever. 

AQUA'TICA.  —  Latin.  Aquatic  ;  be- 
longing or  relating  to  the  water. 

AR'CA. — Latin.  A  chest,  an  ark  or 
coffer.  Systematic  name  of  cer- 
tain mollusks. 

AR'C.E  (ar-kay).— Plural  of  Area. 

ARE'OLA. — A  small  area  or  circle. 

AR'GONAUT. — From  the  Greek,  Argo, 
name  of  a  vessel,  and  Nantes,  a 
navigator.  The  Grecian  princes 
who  attempted  the  conquest  of  the 
Golden  Fleece,  in  the  ship  Argo, 
under  the  command  of  Jason,  were 
called  Argonauts.  Systematic 
name  of  a  cephalopod  (page  28). 

ARGONAU'TA. — Latin.    Argonaut. 

ARTERY. — A  blood-vessel  that  con- 
veys blood  from  the  heart  to  the 
various  organs  of  the  body. 

ABTICULA'TA. — Latin.  Having  joints. 
The  word  animalia,  animals,  being 


understood,  articulata  means  ani- 
mals with  joints,  and  is  applied  to 
insects,  &c. 

ARTI'CULATE  (animals).  —  Having 
joints. 

ARTI'CULATED. — Having  joints. 

ASCI'DIA. — From  the  Greek,  askos,  a 
bottle  or  pouch.  Systematic  name 
of  certain  mollusks. 

ASCI'DIA. — Plural  of  Ascidia. 

ASPE'RGILLUM. — Latin.  A  watering, 
pot. 

AU'DITORY.  —  Belonging  or  relating 
to  the  sense  of  hearing. 

AU'RICLE. — Name  of  one  of  the  cavi- 
ties of  the  heart. 

AURI'CULA. — From  the  Latin,  auris, 
an  ear.  Name  of  a  shell,  from  its 
resemblance  to  the  human  ear. 

AURI'CULO-VENTRI'CULAR  (opening). — 
The  aperture  betwixt  the  auricle 
and  ventricle  of  the  heart  is  so 
called. 

AVI'CULA. — From  the  Latin,  avis,  a 
bird.  Name  of  a  shell  (Jig.  95). 

BATRA'CHIAN  (Ba-tra'-ke-an). — From 
the  Greek,  batrachos,  a  frog.  Be- 
longing to  that  order  of  reptiles 
which  includes  frogs  and  toads. 

BEAK.  —  The    continuation    of   the. 
body   of  univalves   in   which   the 
canal  is  situate. 

BELEM'NITES. — From  the  Greek  be- 
lemnon,  a  dart.  A  genus  of  fbsi. 
sil  dibranchiate  cephalopods,  the 
shells  of  which  are  chambered  and 
perforated  by  a  syphon,  but  in- 
ternal. They  are  long,  straight, 
and  conical,  and  commonly  called 
"  thunder-stones."  They  are  often* 
found  in  chalk. 

BIPHO'RA.  —  From  the  Greek  bis, 
double,  and  phored,  I  bear.  (See 
page  90,  Jig.  114.) 

BIPHO'R^E. — Plural  of  Biphora. 

BI'VALVE. — From  the  Latin  bis,  two, 
and  valva,  doors.  Shells  composed 
of  two  pieces  united  by  a  hinge 
are  termed  bivalves,  as,  for  exam-  • 
pie,  clams,  oysters,  mussels,  &c. 

BOREA'LIS. — Latin.  Northern;  be- 
longing or  relating  to  the  north. 

BOTRY'LLUS. — From  the  Greek,  bo- 
trus,  a  bunch  of  grapes.  (Seepage 
88.) 

BRA'CHIOPOD  (Bra'.ke-o-pod). — From 


CONCHOLOGY.— GLOSSARY. 


103 


the  Greek,  brachion,  an  arm,  and 
pous,  foot  (page  92). 

BRA'CHIOPO'DA.— See  Brachiopod. 

BRA'NCHIA  (Brarik-ea). — Latin.  A 
gill. 

BRA'NCHIA  (bran'k-eay). — Plural  of 
branchia. 

BRANCHIAL,  (brarik-eal),  —  Belonging 
or  relating  to  the  branchise,  or  gills. 

BUC'CAL. — From  the  Latin  bucca,  the 
cheeks.  Belonging  to  the  cheeks. 

BUC'CINUM.  —  Latin.  A  trumpet  or 
horn ;  a  shell. 

BUC'CINA.  —  Latin.  Plural  of  Buc- 
cinum. 

BUCCINOI'DES. — From  buccinum,  and 
the  Greek,  eidos,  resemblance. 
Systematic  name  of  a  family  of 
shells,  the  characters  of  which  re- 
semble those  of  the  Buccinum. 

BY'SSUS. —  From  the  Greek,  bussos, 
fine  flax.  A  bundle  of  silky  fila- 
ments, secreted  by  a  gland  at  the 
foot  of  certain  bivalves,  and  serv- 
ing as  an  organ  of  adhesion  to 
submarine  rocks  and  other  foreign 
bodies. 

CALCA'REOUS. — From  the  Latin,  calx, 
lime.  Partaking  of  the  nature  of 
lime. 

CALMA'RIES. — From  an  old  French 
word,  calmar,  an  inkstand,  or  a  pen- 
case  ;  this  word  is  from  the  Latin, 
calamus,  a  pen.  Name  of  a  family 
of  cephalopods  (pages  23  and  29). 

CALYPTR^E'A. — From  the  Greek,  ka- 
luptra,  a  covering.  Name  of  a 
genus  of  gasteropods  (page  59). 

CALYPTR^;'^;. — Plural  of  Calyptrte'a. 

CAM'ERINES.  —  From  the  Latin,  ca- 
mera, chamber.  Name  of  certain 
microscopic  shells  (page  32). 

CAPI'LLARY. — From  the  Latin,  capil- 
lus,  a  hair.  Hair-like. 

CA'PULUS. — Latin.  A  hilt  or  handle 
(page  58). 

CA  PULOI  DBS.— From  the  Latin,  capu- 
lus,  and  the  Greek,  eidos,  resem- 
blance (page  58). 

CA'PULOI'DA. — Same  as  Capuloides. 

CAR'DIA.— Latin.  Plural  of  cardium, 
a  cockle.  A  genus  of  the  family 

*  of  Cardiacea  (page  84). 

CAR'DIAC. — From  the  Greek,  kardia, 
the  heart.  Belonging  or  relating 
to  the  heart. 


CARDIA'CEA. — From  the  Latin,  car- 
dium, a  cockle.  Systematic  name 
of  a  family  of  acephalous  mollusks 
(page  83). 

CARDIA'CEA. — Plural  of  Cardiacea. 

CAR'DITA. — Genus  of  the  family  of 
Cardiacea. 

CARDINAL  (tooth). — From  the  Latin 
cardo,  a  hinge.  Belonging  or  re- 
lating  to  the  hinge  (pages  99, 
100). 

CARDI'UM. — Latin,  a  cockle. 

CAR'TILAGE. — Gristle. 

CARTILA'GJNOUS.  —  Belonging  or  re- 
lating  to  cartilage. 

CARINA'RTA. — From  the  Latin,  can'wor, 
a  keel.  A  genus  of  heteropodous 
gasteropods  (page  66). 

CA'RINATE. — From  the  Latin,  carina, 
a  keel.  When  a  surface  has  a 
longitudinal  elevated  line  like  the 
keel  of  a  boat. 

CARNI'VOROUS. — From  the  Latin,  caro, 
in  the  genitive  case,  carnis,  flesh, 
and  voro,  I  eat.  Flesh  eating. 

CAS'SIS. — Latin.    A  helmet  (page  54). 

CA'VA  (Vena). — A  name  given  to  the 
two  great  veins  of  the  body,  which 
meet  at  the  right  auricle  of  the 
heart. 

CEPHA'LIC. — From  the  Greek,  kephale, 
the  head.  Belonging  or  relating 
to  the  head. 

CE'PHA LOPODS  (ke'f-a-lo-pods). — From 
the  Greek,  kephale,  head,  and  pous, 
in  the  genitive  case,  podos,  foot.  A 
class  of  mollusks  which  have  the 
head  situated  between  the  body  and 
feet  (page  19). 

CE'PHALOPO'DA. — Latin.  Cephalopods. 

CE'RITA.  )      /0 

CERI'THIUM.     f      (See  page  5^ 

CHAMA  (kama). — From  the  Greek, 
chad,  I  gape.  A  cockle. 

CHAMA'CEA  (ka-ma'-cea). — From  ch.a- 
ma,  a  cockle.  Systematic  name 
of  a  family  of  acephalous  mollusks 
(page  81). 

CHI'TON  (ky'-tori). — From  the  Greek, 
chiton,  a  garment.  Name  of  a  cy- 
clobranch  gasteropod  (page  62). 

CHON'DRUS  (kon'drus). —  From  the 
Greek,  chondros,  cartilage.  Name 
of  a  genus  of  gasteropods  (page 

CHO'ROID  (fro-royed).— From  the  Greek, 


104 


CONCHOLOGY.— GLOSSARY. 


chorivn,  chorion,  and  eidos,  re- 
semblance. Name  of  the  mem- 
brane of  the  eye  which  lines  the 
sclerotica. 

CICA'TRIX. — From  the  Latin,  coscare, 
to  conceal.  The  scar  which  re- 
mains after  the  healing  of  a  wound. 

.  The  "muscular  impressions"  or 
points  where  the  adductor  muscles 
are  attached  in  bivalve  shells  are 
called  cicatrices. 

CICA'TRICES. — Plural  of  cicatrix. 

CI'LIATED. — From  the  Latin,  cilium, 
eyelash.  Fringed,  like  the  eye- 
lashes. 

CINE'REUS. — Latin.  Like  ashes ;  ash- 
colored. 

CIRR'HOPODA,  or  CIRRIPEDIA. —  From 
the  Latin,  cirrus,  a  tendril,  a  curl, 
and  the  Greek,  pous  (podos\  foot. 
Systematic  name  of  a  class  of  mol- 
lusks.  They  are  characterized  by 
having  a  number  of  long,  curled, 
articulated  processes,  analogous 
to  the  feet  of  the  Crustaceans, 
which  project  from  the  central 
aperture  of  the  multivalve  shell 
protecting  them.  They  are  com- 
monly called  barnacles.  This  class 
includes  the  genus  Anatifa  and 
Balanus. 

CLAUSI'LIA. — From  the  Latin,  clau- 
sus,  closed.  A  genus  of  land 
shells,  so  named  because  the  aper- 
ture of  the  shell  is  closed  inter- 
nally by  a  spiral  lid  (page  40). 

CLAVIGE'LLA. — From  the  Latin,  clavis, 
a  nail  (page  88). 

CLEODO'RA. — Name  of  a  genus  of 
pteropod  mollusks  (page  67). 

CLIO. — From  the  Greek,  kleos,  glory 
(page  67). 

CfficuM,  or  CAECUM. — From  the  Latin, 
coecus,  blind.  The  Uind-gut,  so 
called  from  its  being  perforated  at 
one  end  only. 

COLUME'LLA. — Latin,  a  little  column, 
or  pillar.  The  axis  of  a  shell  from 
top  to  bottom  (page  95). 

COMPO'SITA.  —  Latin.     Compounded. 

CON'CHIFE'RA.  —  From  the  Greek, 
conche,  shell,  and  the  Latin,  fero,  I 
bear.  Shell  bearing.  Applied  to 
mollusks  with  bivalve  shells. 

CONCHI'LJAN  (kon-kii'-ean). — Belong- 


ing or   relating  to    shells.     The 
name  of  a  dye  (page  57). 

CONCHO'LOGY.  —  From  the  Greek, 
conche,  a  shell,  and  logos,  a  dis. 
course.  The  science  of  shells. 

CO'NUS. — Latin.     A  cone. 

COR. — Latin.     The  heart. 

CORALLI'OPHAGA.  —  Latin.  Formed 
from  the  Greek,  korallion,  coral, 
and  phagein,  to  eat.  Coral-eating. 

COR'BIS.  —  Latin.  A  twig  basket, 
or  pannier.  Name  of  a  genus  of 
acephalous  mollusks  which  have 
the  external  surface  of  the  shell 
marked  by  ribs  and  transverse 
lines,  resembling  basket-work 
(page  84). 

COR'DIFORM.— From  the  Latin  cor,  m 
the  genitive  case,  cordis,  heart,  and 
forma,  shape.  Heart-shaped. 

COR'NEA.  —  From  the  Latin,  cornu, 
horn.  One  of  the  coats  of  the  eye, 
so  called  because  it  has  some  re- 
semblance to  horn.  It  is  the  ante- 
rior, transparent  part,  through 
which  light  passes. 

CRA'NIAL. — From  the  Latin,  cranium, 
the  skull.  Belonging  or  relating 
to  the  skull. 

From  the  Latin,  crena, 
a  notch.  Having 
rounded  teeth. 

CRE^ULA'TION. — A  rounded  tooth,  or 
notch. 

CREPJ'DULA.  —  Latin.  A  slipper 
(page  58). 

CREPI'DUL^E. — Plural  of  crepidula. 

CRUSTA'CEA. — From  the  Latin,  crus- 
ta,  a  hard  covering.  A  class  of 
free  articulate  animals,  with  arti- 
culated limbs,  a  branchial  respi- 
ration and  a  dorsal  or  ventrical 
heart. 

CRUSTA'CEA.  —  Plural  of  Crustacea. 
Crusta'ceans. 

CRY'STALLINE  LENS. — The  lens  of  the 
eye. 

CY'CLAS. — From  the  Greek,  kuklos,  a 
circle.  A  genus  of  fresh  water 
gasteropods,  so  named  from  the 
circular  form  of  the  shell. 

CY'CLADES. — Plural  of  cyclas. 

CY'CLOBRANCHI'ATA. — From  the  Greek> 
kuklos,  a  wheel,  and  bragcnia,  gills. 
Name  of  an  order  of  mollusks 
(page  61), 


CRE'NULATE. 
CRE'NULATED. 


CONCHOLOGY GLOSSARY. 


105 


CYCLO'STOMA. — From  the  Greek,  ku- 
klos,  a  circle,  and  stoma,  mouth.  A 
genus  of  gasteropods  (page  48). 

CYCLO'STOMA:. — Plural  of  cy clostoma. 

CYMBU'UA. — From  the  Greek,  kum- 
balon,  hollow.  A  genus  of  ptero- 
poda,  commonly  called  the  gondola. 

CYPR^'A. — From  the  Greek,  kupris, 
Venus.  Name  of  a  genus  of  gas- 
teropods. A  cowry. 

CYPIUE'^E. — Plural  of  Cyproea. 

CYPRICAR'DIA. — From  the  Greek,  ku- 
pris, Venus,  and  cardium,  a 
cockle.  A  genus  of  the  family  of 
Chama'cca. 

CYPRI'NA.  —  A  genus  belonging  to 
a  group  of  Cy'clades. 

CYRE'NA. — A  genus  of  the  family  of 
Chama'cea. 

DELPHI'NULA. — Latin.  A  little  dol- 
phin. Name  of  a  genus  of  the 
family  of  Trochoides. 

DEN'TATE.  —  From  the  Latin,  dens, 
tooth.  Marked  with  tooth-like 
projections. 

DEPRESSED  SHELL. — When  the  spire 
is  very  flat. 

DI'APHRAGM. — Midriff. 

DI'BRANCHIA'TA. —  From  the  Greek, 
dis,  two,  and  bragchos,  gills — two- 
gilled.  Name  of  a  division  of  ce- 
phalopods. 

DIBRA'NCHIAL  (di-bra'nk-eal).  —  Hav- 
ing double  gills  or  branchiae. 

DIGITA'TION. — From  the  Latin,  digi- 
tus,  ringer.  A  process  resembling 
a  finger. 

DIMYA'RIA. —  From  the  Greek,  dis, 
two,  and  mudn,  muscle.  All  those 
bivalves  are  so  called  which  have 
two  distinct  and  separate  adductor 
muscles,  and  consequently  two  cor- 
responding muscular  impressions 
on  each  valve. 

DIMYA'RIA. — Plural  of  dimyaria. 

DIPHYLLI'DIA. — From  the  Greek,  dis, 
two,  and  phullon,  leaf.  Name  of  a 
division  of  gasteropods  (page  62). 

DI'SCOID. — From  the  Greek,  diskos,  a 
quoit,  and  eidos,  resemblance. 
This  term  is  applied  to  those  uni- 
valve shells  of  which  the  whorls 
are  disposed  vertically  on  the  same 
plane  so  as  to  form  a  disc ;  as  in 
the  Planorbis  (page  44). 

DOLA'BELLA. — Latin.     A  little  axe. 


Name  of  a  genus  of  gasteropods 
(page  64). 

DO'LIUM.  —  Latin.  A  tun  or  tub. 
Name  of  a  genus  of  gasteropoda 
(page  53). 

DO'NAX.  —  Latin  and  Greek.  A  reed  ; 
an  arrow.  Name  of  a  genus  of 
mollusks  of  the  family  of  Chama'- 
cea (page  84). 

DO'NACES.  —  Plural  of  Donax. 

DO'RIS.  —  A  sea  goddess,  the  daughter 
of  Ocean  and  Thetys.  Name  of  a 
genus  of  nudibranch  gasteropods 
(page  65). 

DO'RSAL.  —  From  the  Latin,  dorsum, 
the  back.  Belonging  or  relating 
to  the  back. 

E'DULIS.  —  Latin.  Edible  ;  that  which 
may  be  safely  eaten. 

EMARGI'NULA.  —  From  the  Latin,  e, 
from,  and  mar  go,  in  the  genitive, 
marginis,  border  or  margin.  A 
genus  of  gasteropods,  character- 
ized by  a  shell  of  simple  conical 
form,  but  having  a  narrow  fissure, 
extending  from  the  margin  to  near 
the  summit  (page  61). 

ENTIRE  OPENING.  —  When  the  opening 
of  a  shell  has  neither  a  notch  or 
canal  on  its  margin,  it  is  said  to 
be  entire  (page  94,  and  page  50, 
Jig.  51). 

E'OLIDIA.  —  Name  of  a  genus  of  gaste- 
ropods  (page  65). 
.—  Pl 


lural  of  Eolidia. 

EPIDE'RMIS.—  From  the  Greek,  epi, 
upon,  and  derma,  skin.  The  cu- 
ticle or  scarf-skin. 

E'QUIVALVE.  —  When  the  two  valves 
of  a  bivalve  shell  are  symmetrical 
they  are  said  to  be  equivalve  (page 
97). 

ETHE'RIA.—  From  the  Greek,  aithd,  I 
shine.  Name  of  a  genus  of  the 
family  of  Ostracea  (page  75). 

ETHE'RIA.  —  Plural  of  Etheria. 

EXCRE'TORY.  —  Applied  to  any  vessel 
or  duct  which  transmits  the  fluid 
secreted  by  a  gland,  either  exter- 
nally or  into  the  reservoir  designed 
to  receive  it. 

EXTRAVASA'TION.  —  From  the  Latin, 
extra,  out  of,  .and  vasa,  vessels. 
Escape  of  fluids  from  vessels  con 
taining  them  and  the  effusion  of 


106 


OONCHOLOGY.— GLOSSARY. 


those  fluids  into  the  surrounding 
textures. 

FASCI'CULUS. — Latin.  A    bundle. 

FASCI'CULI. — Plural  of  fasciculus. 

FI'BROUS. — Composed  of  fibres. 

FILI'FORM. — From  the  Latin,  filum, 
a  thread.  Thread-like. 

FIRO'LA. — Name  of  a  genus  of  gaste- 
ropods  (page  67). 

FIRO'LJE. — Plural  of  Firola. 

FISSURE' LLA. — From  the  Latin,  findo, 
I  split.  A  genus  of  gasteropods 
having  a  split  or  opening  in  the 
top  of  the  shell. 

FISSURE' LL;E. — Plural  of  Fissurella. 

FISTULA'NA. — From  the  Latin,  fistula, 
a  pipe.  Name  of  a  tribe  of  mol- 
lusks  (page  88). 

FISTULA'NA. — Plural  of  Fistulana. 

FO'LLICLE. — From  the  Latin,  follis,  a 
bag.  A  little  bag  or  sack. 

FORAMI'NIFE'RA.  —  From  the  Latin, 
foramen,  a  hole,  and  fero,  I  bear. 
Name  of  a  tribe  of  very  minute 
shells. 

FORMA'TION. — A  geological  term  ap- 
plied to  a  group  of  deposits  or  strata 
apparently  referable  to  a  common 
origin  or  period. 

FO'SSA. — Latin.     A  pit,  a  hollow. 

FOS'S.E. — Plural  of  fossa. 

FRA'GILIS. — Latin.  —  Fragile ;  easily 
broken. 

Fu'cus.— Latin.    Sea-weed. 

Fu'sus. — Latin.     A  spindle. 

GALE' A. — Latin.     A  helmet. 

GAN'GLIA.— Plural  of  ganglion. 

GA'NGLION.— From  the  Greek,  gag- 
glion,  a  knot.  An  enlargement  or 
knot  in  the  course  of  a  nerve  is 
termed  a  ganglion. 

GA'NGLIONIC. — Consisting  of,  or  re- 
lating to  ganglia. 

GA'STEROPODS.  —  From  the  Greek, 
gaster,  belly,  and  pous,  foot.  Sys- 
tematic name  of  a  class  of  mol- 
lusks,  comprehending  those  which 
have  a  ventral  muscular  disc, 
adapted  for  creeping. 

GA'STEROPO'DA. — Latin.    Gasteropods. 

GA'STEROPO'DOUS. — Belonging  or  re- 
lating to  gasteropods. 

GAS'TROCILE'NA. —  From  the  Greek, 
gaster,  belly,  and  chain  o,  I  gape. 
A  genus  of  bivalve  mollusks,  in 


which  a  large  hiatus  or  gape  inter- 
venes  between  the  closed  valves,  on 
the  ventral  aspect  of  the  animal 
(page  88). 

GAS' TROCHEE' N^E. — Plural  of  gastro- 
chaena. 

GE'NUS. — Latin.  A  kindred,  breed, 
race,  stock,  lineage  or  family. 

GE'NKRA. — Latin.     Plural  of  genus. 

GLAND. — An  organ  for  the  purpose 
of  secreting  a  peculiar  fluid,  &c. 

GLA'NDULAR. — Relating  to  glands. 

GLAU'CUS. — From  the  Greek,  glaukos, 
blue.  Name  of  a  genus  of  mollusks 
(page  66). 

GLO'BOSE. — Globe-like ;  globular. 

GLYCY'MERA,  or  GLYCI'MERIS. —  Name 
of  a  genus  of  bivalve  mollusks 
(page  86). 

GRYPH^E'A. — From  the  Greek,  gru- 
pos,  incurved.  A  genus  of  mol- 
lusks of  the  family  of  Ostracea 
(page  73). 

HA'LIOTIS. — From  the  Greek,  als,  the 
sea,  and  ous,  the  ear.  Name  of  a 
genus  of  gasteropods  (page  60). 

HALIO'TIDES. — Plural  of  Haliotis. 

HAR'PA. — Latin.     A  harp. 

HELICI'NA. — Name  of  a  genus  of  gas. 
teropods. 

HE'LIX. — From  the  Greek,  elix,  a 
spiral,  a  whorl.  Name  of  a  genus 
of  gasteropods  (page  39). 

HELI'CES.— Plural  of  Helix. 

HEMI'CYCLO'STOMA. — From  the  Greek, 
emisus,  half,  kuklos,  round,  and 
stoma,  mouth.  Name  of  a  tribe  of 
gasteropods  (page  49). 

HERBI'VOR,OUS.  —  From  the  Latin, 
herba,  plants,  and  voro,  I  eat. 
Plant-eating ;  applied  to  animals 
that  feed  on  vegetables. 

HERMA'PHRODITE. — From  the  Greek, 
ermes,  Mercury,  and  aphrodite, 
Venus.  An  organized  body,  com- 
bining in  reality  or  appearance  the 
characteristics  of  both  sexes. 

HE'TEROPODS. — From  the  Greek  etc- 
ros,  various,  and  pous,  foot.  The 
name  of  an  order  of  gasteropods. 

HE'TEROPO'DA.  —  Latin.  Heteropods 
(page  66). 

HE'TEROPO'DOUS. — Belonging  or  relat- 
ing to  heteropods. 

HIA'TUS.  —  Latin.  A  yawning,  a 
gape. 


CONCHOLOGY.— GLOSSARY. 


107 


HIPPO'NYX.  —  From  the  Greek,  ippos, 

a  horse,  and  onux,  nail.     Name  of 

a  genus  of  gasteropods  (page  58). 
HYAL^E'A.  —  From   the   Greek,  ualos, 

glass.     A  genus  of  beautiful  ptero- 

pods,   remarkable    for   the    trans- 

parency  and  delicacy  of  the  shell 

(page  67). 
HYDA'TIS.  —  Latin.     Formed  from  the 

Greek,  udor,  water.    Specific  name 

of  a  mollusk. 
IM'BRICATE.  —  Placed  like  the  tiles  of  a 

house. 
INCLU'SA.  —  From  the  Latin,  includo, 

I  enclose.     Name   of  a   tribe  of 

acephalous  mollusks. 
INCURV'ED.  —  When  a  part  is  turned 

inwards. 
INE'QUILATERAL.  —  When  the  anterior 

and  posterior  sides  make  different 

angles  with  the  hinge. 
INE'QUIVALVE.  —  Where  one  valve    is 

more  convex  than  the  other,  or  dis- 

similar in  other  respects,  as  in  the 

common  oyster. 
IN'FEROBRANCHIA'TA.  —  From  the  Lat- 

in, infer  us,  below,  and    bronchia, 

gills.     Name  of  an  order  of  gas- 

teropods which  have  the  branchiae 

below  the  mantle  (page  62). 
INTE'GUMENT.  —  F-rom   the  Latin,   te- 

gere,   to  cover,  the   covering,  the 

skin. 
IN'TERGANGLIO'NIC.  —  Applied      to 

nerves  which  are  between  ganglia. 
IN'TERNODE.  —  The  space  between  one 

knot  or  joint  and  another. 
INTERRU'PTED.  —  Divided,  separated. 


or  joint  of  the  spine  or  back-bone. 
A  division  of  the  animal  kingdom, 
embracing  mollusks,  insects,  and 
other  animals  which  have  no  ver- 
tebrae, or  internal  bony  skeleton. 

INVE'RTEBRATE.  —  Without  vertebrae. 

IN'VOUJTE.  —  Having  the  exterior  lip 
turned  inwards  at  the  margin,  as 
in  the  CyprsBte. 

INVOLUTION.  —  That  part  which  in- 
volves  or  inwraps  another. 

ISO'CARDIA.  —  From   the   Greek,  isos, 
like,  and  kardia,  heart.     Name  of 
a  genus  of  Chama'cea  (page  82). 
'  of  Isocardia. 


JANTHI'NA. — From  the  Greek,  ianthon, 
violet  colour.  A  genus  of  the 
family  of  Trochoides. 

LA'BIAL. — From  the  Latin,  labium, 
lip.  Belonging  or  relating  to  the 
lips. 

LACI'NIATE. — Jagged,  or  cut  into  ir- 
regular segments. 

LA'CUNOSE.  —  Having  the  surface 
covered  with  pits. 

LAME'LLA. — Latin.  A  little  thin  plate 
or  piece. 

LAME'LL^E. — Plural  of  lamella. 

LAME'LLIBRA'NCHIATA-  —  From  the 
Latin,  lamella,  a  thin  plate,  and 
bronchia,  gills.  An  order  of  aceph- 
alous mollusks. 

LAME'LLIBRANCH. — Belonging  to  the 
lame  'llibra'nchiata. 

LA'MINA. — Latin.  A  plate,  or  thin 
piece  of  metal  or  bone. 

LA'MINME. — Plural  of  lamina. 

LA'MINATED. — Divided  into  distinct 
laminae. 

LAPI'LLUS. — Latin.  •  A  little  stone. 

LENTI'CULAR. — From  the  Latin,  len- 
ticula,  a  little  lens,  a  lentil. 
Shaped  like  a  lens. 

LI'MA. — Latin.  A  file.  Name  of  a 
genus  of  the  family  of  Ostracea. 

LI'MAX. — Latin.     A  slug,  a  snail. 

LIMA'CES. — Plural  of  Umax. 

LIMB. — The  margin  of  bivalve  shells. 

LIMN^E'A. — From  the  Greek,  limne,  a 
pool.  Name  of  a  genus  of  fresh- 
water snails. 

LI'NEAR. — Composed  of  lines. 

LI'NEATE. — Marked  with  lines. 

LI'NGULA.— Latin.  A  little  tongue. 
Name  of  a  genus  of  bivalves  (page 
89). 

LI'NGULA. — Plural  of  Lingula. 

LITHO'DOMUS.  —  From  the  Greek, 
lithos,  stone,  and  demo,  I  build. 
Name  of  a  genus  of  bivalves  found 
in  rocks  and  stones,  inhabiting 
cavities  which  they  form  for  that 
purpose. 

LITHO'DOMI. — Plural  of  Lithodomus. 

LJ'TTORAL. — Belonging  to  the  shore. 

LITTORI'NA. — From  the  Latin,  litus, 
the  sea-shore.  A  genus  of  the 
family  of  Trochoides  (page  49). 

LITTO'REUS.  —  Latin.  Belonging  ox 
relating  to  the  sea-shore. 


108 


CONCHOLOGY.— GLOSSARY. 


LO'BATED. — Rounded  at  the  edges. 

LOBE. — A  round  projecting  part. 

LO'LIGO. — Latin.     A  calmary. 

LOLIGO'PSIS. — A  calmaret;  a  little 
calmary. 

LONGITU'DINAL. — The  length  of  the 
shell  from  the  apex  to  the  base. 

LUBRI'CITY. — Smoothness  of  surface, 
slipperiness. 

LU'NATED. — Formed  like  a  half-moon. 

LUNU'LATED. — Crescent-shaped. 

LU'NULE. — A  crescent-like  spot  or 
mark  situated  near  the  anterior 
and  posterior  slopes  in  bivalve 
shells. 

LU'NIFORM. — In  the  shape  of  a  cres- 
cent or  half-moon. 

LUTRA'RIA. — Genus  of  the  family  of 
Inclusa. 

MACTRA.  —  Latin.  A  kneading- 
trough.  Name  of  a  genus  of  bi- 
valves. 

MA'DREPORE. — A  hybrid  compound 
of  the  French  madre,  spotted,  and 
Latin,  porus,  a  pore.  Name  of  a 
genus  of  zoophytes. 

MA'GILUS. — Name  of  a  genus  of  gas- 
teropods. 

MA'GUS. — Latin.     Magical. 

MA'LLEUS. — Latin.  A  hammer.  A 
genus  of  Ostracea. 

MA'NDIBLE. — From  the  Latin,  man- 
dibula,  a  jaw.  The  jaw  of  a  bird. 

MAN'TLE.— The  external  fold  of  the 
skin  of  mollusks. 

MA'RGARITI'FERA. — Latin.  From  mar- 
garitum,  a  pearl,  and  fero,  I  bear. 
Pearl-bearing. 

MA'RGIN. — The  whole  circumference 
or  outline  of  the  shell  in  bivalves. 

MA'RGINATED. — Having  a  prominent 
margin  or  border. 

MEDITERRA'NEA. — Latin.  Belonging 
or  relating  to  the  Mediterranean. 

MEDU'LLARY. — From  the  Latin,  me- 
dulla, the  marrow.  Belonging  or 
relating  to  nervous  matter. 

MELA'NIA. — From  the  Greek,  melas, 
black.  Genus  of  fresh- water  gas- 
teropods. 

MELEAGRI'NA. — From  the  Greek,  me- 
leagris,  a  guinea-hen.  A  genus 
of  the  family  of  Ostracea. 

MEM'BRANOUS. — Belonging  or  relat- 
ing to  membrane. 

ME'SENTERY. — From  the  Greek,  me- 


sos,  in  the  middle,  and  enleron,  in- 
testine. A  membrane  which 
serves  to  retain  the  intestines  in 
their  proper  situation. 

METAMO'RPHOSIS. — From  the  Greek, 
meta,  indicating  change,  and  mor- 
phe,  form.  Transformation. 

MICROSCO'PIC. — From  the  Greek,  mi- 
kros,  little,  and  skoped,  I  view.  Di- 
minutive. Not  easily  seen  with- 
out the  aid  of  a  magnifying-glass. 

MI'TRA. — Greek.  A  head-band,  or 
diadem.  A  genus  of  gasteropods. 

MODIO'LUS.  —  Latin.  A  bucket.  A 
genus  of  mussels. 

MO'LECULE. — An  atom. 

MOLLU'SCA. — From  the  Latin,  mollis, 
soft.  Name  of  the  second  branch 
of  the  animal  kingdom. 

MO'LLUSK. — A  soft  animal. 

MO'NODON. — From  the  Greek,  monos, 
single,  and  odous,  tooth.  A  genus 
of  the  family  of  Trochoides. 

MONODON'TA. — Latin.     Monodons. 

MONO'MYA'RJA.  —  From  the  Greek, 
monos,  single,  and  muon,  muscle. 
Bivalves  which  have  only  one  ad- 
ductor  muscle. 

MU'CRONATE. — Ending  in  a  sharp, 
rigid  point. 

MU'LTIVALVE.  —  From  the  Latin, 
multus,  many,  and  valvtB,  valves. 
Composed  of  several,  or  more  than 
two  calcareous  pieces  or  valves. 

MULTILO'CULAR. — From  the  Latin, 
multus,  many,  and  loculus,  a  lodge. 
Many-chambered  ;  consisting  of 
several  divisions. 

MU'REX.  — ^.Latin.  A  shell-fish.  A 
genus"  o^fcasteropods. 

MU'RICES.— Plural  of  Murex. 

MU'RICATED.  —  Clothed  with  sharp 
spines. 

MU'SCLE. — Fleshy  fibres  capable  of 
contraction  and  relaxation. 

MU'SCUI.AR. — Belonging  or  relating 
to  muscle. 

MU'SSEL. — An  acephalous  mollusk. 

MY'A. — From  the  Greek,  muon,  a 
muscle.  An  acephalous  mollusk. 

MYTILA'CEA. — From  the  Greek,  mu- 
tilos,  a  mussel.  Name  of  a  family 
of  mollusks. 

MY'TILUS. — Latin.     A  mussel. 

NA'CRE. — From  the  Spanish,  nacar, 
mother-of-pearl. 


CONCHOLOGY.— GLOSSARY. 


109 


NA'CREOUS.— Of  the  nature  of  mother- 
of-pearl. 

NA'SSA. — Latin.  A  net,  a  snare.  A 
genus  of  gasteropods. 

NA'TICA. — Latin.  Name  of  a  genus 
of  gasteropods  (pages  34  and  51). 

NAU'TILUS. — From  the  Greek,  Nau- 
tilos,  name  of  the  Argonaut.  A 
genus  of  cephalopods. 

NE'MORAL.— From  the  Latin,  nemus, 
a  wood.  Belonging  or  relating  to 
a  wood  or  grove. 

NERI'TA. — Latin.  A  shell-fish.  A 
genus  of  gasteropods  (page  51). 

NERITI'NA. — Latin.  Diminutive  of 
Nerita.  A  genus  of  gasteropods 
(page  51). 

NERV'OUS. — Belonging  or  relating  to 
the  nerves. 

NILO'TICUS. — Latin.  Belonging  to 
the  Nile. 

NI'TED. — From  the  Latin,  niteo,  I 
shine.  Glossy. 

NODO'SE. — Knotty. 

NU'CHA  (nu-ka). — The  nape  of  the 
neck. 

NU'CLEUS.  —  A  kernel.  A  centre 
around  which  matter  has  accumu- 
lated. 

NU'DA. — Latin.     Naked. 

NU'DIBRANCH.— Relating  to  the  Nu- 
dibranchiata. 

NU'DIBRANCHIA'TA. — From  the  Latin, 
nudus,  naked,  and  branchia,  gills. 
Name  of  an  order  of  gasteropods. 

NUMMULI'TES. — From  the  Latin  num- 
mus,  money,  and  the  Greek,  lithos, 
stone.  An  extinct  genus  of  cepha- 
lopods, of  a  thin  lenticujar  shape, 
divided  internally  into  small  cham- 
bers. These  occur  so  abundantly 
in  some  parts  of  the  chalk  forma- 
tion, that  the  name  of  nummulite 
limestone  is  given  to  the  strata  so 
characterized. 

OB'LONG-O'VATE. — Egg  shaped,  or  oval. 

OB'SOLETE. — Indistinct,  not  well  de- 
nned. 

O'CELLATED. — From  the  Latin,  ocu- 
lus,  an  eye.  Marked  with  eye- 
like  spots. 

O'CHRKOUS  (ok1 -re-us}. — Of  the  colour 
of  yellow  ochre. 

O'cTOPus. — From  the  Greek,  oJtto, 
eight,  and  pous,  foot.  Name  of  a 
genus  of  cephalopods. 

10 


OCTOPO'DIA. — A  tribe  of  cephalopods. 

OZso'pHAGEAL.  —  Belonging  to  the 
oesophagus. 

CEso'pHAGus. — Latin.     The  gullet. 

OF'FUSCATED.  —  Darkened,  clouded, 
dimmed. 

OFFICINA'LIS.  —  Latin.  Officinal. — 
From  officina,  a  shop.  Applied  to 
what  is  ready  prepared. 

OLI'VA. — Latin.  An  olive.  A  genus 
of  gasteropods. 

OLIVA'CEOUS. — Being  of  a  greenish 
olive  colour. 

ONCHI'DIUM. — A  genus  of  gasteropods 
(page  41). 

OPA'QUE. — From  the  Latin,  opacus, 
dark.  Incapable  of  transmitting 
light. 

OPE'RCULUM.  —  From  the  Latin, 
operio,  I  cover.  The  lid  or  door 
which  covers  anything. 

O'PTIC. — From  the  Greek,  optomai,  I 
see.  The  principal  nerve  of  vision, 
is  so  called. 

ORBI'CULA. — From  the  Latin  orbis,  a 
circle.  A  genus  of  brachiopod 
mollusks  (page  90). 

ORBI'CULAR.  —  Spherical,  circular, 
round. 

O'RGAN. — From  the  Greek,  organon, 
an  instrument.  Part  of  an  organ- 
ized being,  destined  to  exercise 
some  particular  function. 

ORGANIZA'TION. — A  mode  of  structure. 

OSTRA'CEA. — Name  of  a  family  of 
bivalves. 

OS'TREA. — Latin.  An  oyster.  Name 
of  a  genus  of  the  family  of  Os- 
tracea. 

O'VARIES.  —  Female  organs  which 
contain  the  ova  or  eggs. 

O'VATE. — Shaped  like  the  longitudi- 
nal section  of  an  egg. 

O'VIDUCT. — From  the  Latin  ovum,  an 
egg,  and  duco,  I  conduct.  The 
tube  which  conveys  the  ovum  from 
the  ovary. 

OVI'PAROUS. — From  the  Latin,  ovum, 
an  egg,  and  pario,  I  produce.  Ap- 
plied to  animals  whose  young  are 
produced  by  means  of  eggs. 

O'vom. — Oval. 

O'VULA. — From  the  Latin,  ovum,  an 
egg.  A  genus  of  gasteropods. 

O'VULJE. — Plural  of  ovula. 

PA'LATINE.— Relating  to  the  palate. 


110 


CONCHOLOGY.— GLOSSARY. 


PA'LLIAL. — Belonging  or  relating  to 

the  pallium. 
PA'LLIUM. — Latin.     A   cloak.      The 

mantle  of  mollusks  is  so  called. 
PALUDI'NA. — In  the  plural  Paludinee. 

From  the  Latin,  palus,   a   marsh. 

Name  of  a   genus  of  fresh-water 

gasteropods. 
PAN'CREAS. — A  gland  situated  in  the 

abdomen. 
PAPI'LLA. — Plural,    papilla.      Latin. 

A  nipple.    A  nipple-like  eminence. 
)  Having     the     surface 
.        coverfdwithpimp,eS 

}    or  dots. 
PA'PILLOSE. — Pimpled,  dotted. 
PAPYRA'CEOUS. — From  the  Latin,  pa- 
pyrus, a  sort  of  paper.     Thin   as 

paper. 
PARI'ETES. — From  the  Latin,  paries, 

a  wall.     A  name   given   to   parts 

that    form     the     enclosures — the 

limits  of  different  cavities  of  the 

body. 
PARMACE'LLA.  —  From     the     Latin, 

parma,  a  round  buckler.     A  genus 

of  naked  gasteropods. 
PATE'LLA. —  In    the    plural    patella. 

Latin.     The   knee-pan.     A  genus 

of  gasteropods  (page  61). 
PA'TULOUS. — With  a  gap  or  opening. 
PE'CTEN. —  In    the     plural    pectenes. 

Latin.     A  comb.     A  genus  of  the 

family  of  Ostracea  (page  73). 
PEC'TINA'TA. — Latin.     Pectinated. 
PECTINATED. — Resembling   the  teeth 

of  a  comb. 
PECTI'NIBRANCH. — From    the    Latin, 

pecten,  comb,  and    bronchia,  gills. 

Relating  to  the  Pectinibranchiata. 
PECTINIBRANCHIA'TA. —  Name   of   an 

order  of  gasteropods. 
PECTU'NCUI-US. — Latin.      Name  of  a 

genus  of  the   family  of  Ostracea 

(page  78). 

PE'DICLE. — A  support.     A  little  foot. 
PE'DIFORM. — Foot-shaped. 
PEDU'NCLE. — A  foot- stalk  or  tube  on 

which  anything  is  seated. 
PEDU'NCULATE. — Having  a  peduncle. 
PELA'GIC. — Belonging  to  the  deep  sea. 
PE'LLICLE. — A  thin  skin  or  film. 
PENU'LTIMATE. — Next  to  the  last. 
PE'RNA. — In  the  plural  pernce.    Latin. 

A    gammon.      A    genus    of    the 

family  of  Ostracea  (page  75). 


PERTCA'RDIUM. — The  sack  which  con. 

tains  the  heart. 
PETRACO'LA. — From  the  Latin,  pelra, 

a  stone,  and  colo,  I  inhabit.    Name 

of  a  family  of  Ostracea  (page  85). 
PHASIANE'LLA. — From  the  Greek,  pha. 

sianos,  a   pheasant.      A  genus  of 

gasteropods  (page  50). 
PHARY'NX. — The   swallow.     The   su- 
perior opening  of  the  gullet. 
PHO'LAS. —  In    the    plural    pholades. 

From  the  Greek,  pholtos,  a  lurking. 

place.     A  genus  of  the  family  of 

Iriclusa  (page  87). 

PHOSPHO'RIC.  )  Emitting     light 

PHOSPHORE' SCENT.    (    in  the  dark. 
PHYLLI'DIA.  —  From       the      Greek, 

phullon,  a  leaf.     Name  of  a  tribe 

of  mollusks  (page  62). 
PHY'SA. — From     the    Greek,    phusa, 

a  bubble.     A  genus  of  fresh-water 

snails  (page  42). 
PI'CA. — Latin.     Black  as  pitch. 
PILEO'PSIS. — From  the   Greek,  pilos, 

a   hat.      A  -  genus   of  gasteropods 

(page  58). 
PI'LLAR. — The  internal  continuation 

of  the  columella,  and  extends  from 

the  base  to  the  apex. 
PI'NNA. — Latin.    In  the  plural  pinna. 

A  fin,  a  wing.     A   genus   of  the 

family  of  Ostracea. 
PI'NNATED. — Winged. 
PLANO'RBIS. — From  the  Latin,  planist 

flat,  and  orbis,  an  orb,  a  circle.     A 

genus  of  marsh-snails  (page  42). 
PLI'CA.— Latin.     A  fold. 
PLI'CATE. — Folded  or  plaited,  as  in  the 

pillar  of  the  Volute  tribe. 
PLEUROBR^'NCHUS     (plu-ro-brari-kus). 

— From   the   Greek,  pleura,  side, 

and  bragchia,  gills.     A  genus  of 

gasteropods  (page  63). 
PLEUROBRA'NCHI — (plu-ro-bran'-ki). — 

Plural  of  Pleurobranchus. 
PLUMO'SE.  —  Having   a   feathery  ap- 
pearance. 

PO'LYPI. — Plural  of  Polypus. 
PO'LYPUS. — From   the   Greek,  polus, 

many,  and  pous,  foot.     A  genus  of 

radiate  animals. 
POLYTHA'LAMOUS. — From   the   Greek, 

polus,  many,  and  thalamos,  cham- 
ber.    Having  many  chambers. 
POR'CATE.  —  Marked     with      raised 

longitudinal  lines. 


CONCHOLOGY— GLOSSARY. 


Ill 


PORCELLA'NA. — Latin.     Porcelain. 
PORRE'CTED. — Projecting-. 
POST-CESOPHA'GEAL..  —  Situate    behind 

the  oesophagus. 
POUNCE. — A  powder  to   prevent   ink 

from  spreading-  after  erasures. 
PREHE'NSION. — The  act  of  laying  hold 

of  and  conveying  the   food  to  the 

mouth. 
PROBO'SCIS. — A  trunk,  a  prolongation 

of  the  nose. 

PRODUCED. — Lengthened  out. 
PSAMMO'BIA. — From  the  Greek,  psam- 

mos,  sand.     A  genus  of  bivalves. 
PTERO'CERA.  —  From      the      Greek, 

pteron,  wing,  and  keras,  a  horn.    A 

genus  of  gasteropods  (page  55). 
PTERO'PODA.  —  From      the      Greek, 

pteron,   a    wing,   and    pous,    foot. 

Name  of  a  class  of  mollusks  (page 

67). 
PUNC'TUATED. — From  the  Latin,  punc- 

tum,  a  point.     Having  small  hol- 
lows   like    the     punctures    of    a 

thimble. 
PU'LMONARY. — Belonging  or  relating 

to  the  lungs. 

PULMONE'A. — Latin.     Pulmonary. 
PU'PA. — Latin.     A  puppet.     A  genus 

of  snails. 
PUR'PURA. — Latin.    Purple.    A  genus 

of  the  family  of  Buccinoides  (page 

53). 
PYLO'RUS. — The   right   orifice  of  the 

stomach. 

PY'RIFORM. — Pear-shaped. 
PYROSO'MA. — In  the  plural  pyrosomtB. 

From   the  Greek,  pur,   fire,   and 

soma,  body      A  genus  of  mollusks 

(page  92). 
QUADRA'NG  ULAR.  —  Having     four 

angles. 
QUA'DRIPLICATED. — Having   four 

plaits. 
RADIA'TA. — Latin.     Name  of  a  class 

of  Zoophytes. 
RA'DIATE. — From  the  Latin,  radius,  a 

ray.     Furnished  with  rays. 
RE'CTUM. — The   terminating   portion 

of  the  intestine. 
RECCJ'RVED. — Bowed  back. 
REFLE'CTED. — Bent  backwards. 
REFKA'CTED. — Abruptly   bent,   as   if 

broken. 

RE'NIFORM. — Kidney -shaped. 
REPA'ND. — With  a  serpentine  margin. 


RE'PLICATED.  —  Folded  so  as  to  form  a 

groove  or  channel. 
RESPIRA'TION.  —  The  act  or  function  of 

breathing. 
RESPI'RATORY.  —  Relating   to   respira- 

tion. 
RETI'CULATED.  —  Formed  like  a  piece 

of  net-  work. 
RETRA'CTILE.  —  Susceptible   of   being 

drawn  back. 

RETROFLE'CTED.  —  Bent  backwards.. 
RETROU'SSE.—  Backed  up,  turned  up. 
RETROVE'RTED.  —  Turned  back. 
RETU'SE.  —  Ending  in  an  obtuse  sinus. 
RETUN'DATED.  —  Blunted  or  turned  at 

the  edge. 

RE'VOLUTE.  —  Rolled  backwards. 
RI'MA.  —  The   interstice  between   the 

valves   when    the    hymen    is    re- 

moved. 
ROS'TRUM.  —  The   beak.     The   exten- 

sion of  that  part  of  the   shell   in 

which  the  canal  is  situated. 
'  ROTO'ND.  —  Round,    circular,    spheri- 

cal. 

RU'FOUS.  —  Of  a  reddish  colour. 
RU'FUS.  —  Latin.     Reddish. 
RU'GOSE.  —  Rugged,  full  of  wrinkles. 
SALI'VA.  —  The  fluid   secreted  in  the 

mouth  by  the  salivary  glands. 
SA'LIVARY.  —  Relating  to  saliva. 
SANGUI'NOLA'RIA.  —  From    the    Latin, 

sanguis,  blood.     Name  of  a  genus 

of  acephalous  mollusks. 
SANGUINA'CEOUS.  —  Of  a  blood  colour, 

or  resembling  blood. 
SCA'BROUS.  —  From   the  Latin,  scaber, 

rough.     Rough,  harsh,  rugged,  or 

like  a  file. 
SCALA'RIA.  —  From  the  Italian,  scala, 

a  ladder,  or  series  of  stairs.    Name 

of  a  genus  of  gasteropods. 
SCA'LLOPED.  —  Indented  at  the  edges. 
SCLERO'TICA.  —  From  the  Greek,  skle- 

ros,   hard.     One   of  the   external 

membranes  of  the  eye-ball. 
SCORBI'CULATE.      Pitted,   having   the 

surface  covered  with  hollows. 


SCUTIBRANCHIA'TA.  —  From  the  Latin, 
scutum,  a  shield,  and  branchia,  gills. 
An  order  of  gasteropods. 

SEAM.  —  The  line  formed  by  the  union 
of  the  valves. 

SE/CONDARY  FORMA'TION.  —  A  series  of 


112 


CONCHOLOGY.— GLOSSARY". 


stratified  rocks  with  certain  cha- 
racters  by  which  they  are  distin- 
guished from  the  primary  rocks. 
By  the  term  formation  geologists 
understand  a  series  of  rocks  of  the 
same  age.  Those  rocks  which 
were  first  formed  are  called  pri- 
,  mary ;  those  formed  next  in  suc- 
cession are  secondary  ;  and  so  on. 

SECRE'TION. — From  the  Latin,  secer- 
nere,  to  separate.  The  process  by 
which  organic  structure  is  enabled 
to  separate  from  the  fluids  circu- 
lating in  it,  other  different  fluids. 
These  separated  fluids  are  also 
called  secretions. 

SECRE'TORY. — Belonging  or  relating 
to  secretion. 

SEMICOR'NEOUS.  —  From  the  Latin, 
semi,  half,  and  cornu,  horn.  Half 
or  partly  horny  in  its  nature. 

SE'PIA.  —  Latin.  A  cuttle-fish.  A 
kind  of  paint  made  from  this  ani- 
mal. A  genus  of  cephalopods. 

SE'PTIFORW. — From  the  Latin,  sep- 
tum, a  partition.  In  the  shape  of  a 
partition. 

SE'RRATED. — From  the  Latin,  sera,  a 
saw.  Like  the  teeth  of  a  saw. 

SE'RRULATED. — Very  minutely  ser- 
rated. 

SE'TA.— Latin.    A  bristle. 

SETA'CEOUS.  )  Bristly ;    covered   with 

SE'TOSE.         £    bristles. 

SIGARE'TUS. — A  genus  of  gasteropods. 

SILIQUA'RIA. — From  the  Latin,  si'li- 
qua,  a  pod.  A  genus  of  gastero- 
poda tubulibranchiata. 

SI'NISTER. — The  left. 

SI'NUS. — A  groove  or  cavity. 

SIPHONA'RIA. — From  the  Greek,  si- 
phon, a  tube.  An  order  of  cepha- 
lopods. 

SJPHU'NCULUS. —  A  cylindrical  canal 
perforating  the  partitions  in  poly- 
thalamous  shells. 

SO'LAR. — From  the  Latin,  sol,  the  sun. 
Belonging  or  relating  to  the  sun. 

SOLA'RIUM. — Latin.  A  sun-dial.  A 
genus  of  the  family  of  Trochoides. 
(page  46). 

SOLEMY'A.— A  genus  of  the  family  of 
Inclusa. 

SO'LEN.— From  the  Greek,  solen,  a 
tube.  A  genus  of  acephalous  mol- 
lusks  (page  86), 


SPA'TULATE. — Rounded  and  broad  at 
one  end,  and  becoming  narrow  like 
a  battledore  or  spatula. 

SPHEROI'DAL. — Resembling  a  sphere 
or  globe. 

SPI'NAL. —  Belonging  or  relating  to 
the  spine. 

SPI'NOUS.   )  Covered   with    thorn -like 

SPI'NY.       £    processes  or  spines. 

SPIRE. — All  the  whorls  of  univalve 
shells,  except  the  one  in  which  the 
aperture  is  situated,  which  is  term, 
ed  the  body. 

SPI'RAL. — Twisted  like  a  corkscrew. 

SPLEEN. — An  organ  of  the  body,  the 
use  of  which  is  not  known  :  it  is 
vulgarly  called  the  melt. 

SPON'DYLUS. — In  Greek,  spondulos,  a 
vertebra.  A  genus  of  bivalves,  in 
which  the  teeth  of  the  hinge  lock 
into  each  other,  like  the  vertebrae 
of  the  spine. 

SQUA'MOSE. — From  the  Latin,  squama, 
a  scale.  Scaly. 

STE'LLATED. — Consisting  of  star-like 
figures. 

STRA'TA. — Latin.     Plural  of  stratum. 

STRA'TUM. — Latin.     A  bed,  a  layer. 

STRI'A. — Latin.  In  the  plural  stria. 
A  diminutive  channel  or  crease. 

STRI'ATED. — Scored,  or  covered  with 
fine  thread-like  lines. 

STRO'MBUS. — Latin.  In  Greek  strotn- 
bos,  a  shell-fish.  A  genus  of  gas- 
teropods. 

STY'LET. — A  small  style  or  slender 
process. 

SUBAR'CUATED. — Somewhat  arched. 

SUBCO'NIC. — Somewhat  conical. 

SuBtESOPHA'cEAL. — Placed  beneath  the 
oesophagus. 

SUB'ROTUND. — Nearly  globular. 

SUB'ULATE. — Awl-shaped. 

SUCCI'NEA. — From  the  Latin,  sue. 
cinum,  amber.  A  genus  of  gaste- 
ropods, so  called  from  the  trans- 
parent texture  and  amber  colour 
of  the  shell. 

SU'LCATED. — Furrowed. 

SU'LCI. — Plural  of  sulcus. 

SU'LCUS. — Latin.     A  furrow. 

SU'MMIT. — The  tip  or  apex. 

SU'PERFICIES. — From  the  Latin,  super, 
above,  and  fades,  face.  The  sur- 
face. 

SUPERPO'SED. — From  the  Latin,  supert 


CONCHOLOG7.— GLOSS  AK  Y. 


113 


above,  and  pono,  I  place.  Laid 
one  upon  another ;  lying  above. 

SU'TURE. — The  seam,  or  fine  spiral 
line  which  separates  the  whorls  or 
wreaths. 

SY'PHON — From  the  Greek,  siphon, 
a  tube. 

TACT. — The  sense  which  gives  the 
perception  of  touching.  Touch  is 
active  ;  tact  passive. 

TECTIBRANCHIA'TA.  —  From  tego,  I 
cover,  and  branchia,  gills.  Name 
of  an  order  of  gasteropods. 

TEGUME'NTARY. — Relating  to  the  tegu- 
ment or  covering. .  . 

TELLI'XA.  —  In  the  plural  tellince. 
From  the  Greek,  telline,  a  species 
of  mussel.  A  genus  of  acephalous 
mollusks. 

TEN'TACLE.— A  feeler. 

TENTA'CULA. — The  feelers  of  snails. 

TENTA'CULAR. — Belonging  or  relating 
to  tentacles. 

TENTA'CULUM. — Latin.     A  feeler. 

TERE'BRA. — Latin.  From  terebro,  I 
bore.  A  genus  of  gasteropods. 

TEREBRA'TULA.  —  Plural,  terebratula. 
A  genus  of  acephalous  mollusks 
(page  89). 

TERE'DO. — Latin.     A  ship-worm. 

TERE'DINES. — Plural  of  teredo. 

TERRE'STRIA. — Latin.     Terrestrial. 

TER'TIARY  FORMA'TION,  or  strata. — A 
series  of  sedimentary  rocks  which 
lie  above  the  primary  and  second- 
ary strata,  and  distinguished  from 
them  by  their  organic  remains. 

TE'SSELATED.  —  Chequered  like  a 
chess-board. 

TESSELA'TUS. — Latin.     Tesselated. 

TESTA'CEA. — From  the  Latin,  testa,  a 
shell.  An  order  of  acephala  cover- 
ed with  a  testaceous  shell. 

TESTA'CEOUS. — Consisting  of  carbo- 
nate of  lime  and  animal  matter. 

TESTACE'LLA.  —  A  genus  of  snails 
(page  39). 

TE'TRABRANCH. — Having  four  bran- 
chiae. 

TETRABRANCHIA'TA. — From  the  Greek, 
tetteres,  four,  and  bragchia,  gills, 
Name  of  an  order  of  gasteropods. 

TE'TRAGONAL. — Four  cornered. 

THORA'CIC. — Belonging  to  the  thorax. 

THO'RAX. — Latin.     The  chest. 

TRANSVE'RSE.  —  Placed  crosswise. 
10* 


When  the  breadth  of  a  shell  is 
greater  than  its  length,  it  is  termed 
transverse. 

TRAPE'ZIFORM. — Shaped  like  a  trape- 
zium. 

TRIDA'CXA. — A  genus  of  the  family 
of  Chama'cea. 

TRICO'RNIS." — From  the  Latin,  tres, 
three,  and  cornw,  horn.  Three 
horned. 

TRIGO'NIA. — From  the  Greek,  trigo- 
nos,  three-cornered.  A  genus  of 
the  family  of  Ostracea. 

TRIGO'NAL. — Three-cornered. 

TRITO'NIA. — A  genus  of  gasteropods. 

TROCHO'IDES. — From  the  Greek,  tro~ 
chos,  a  wheel,  and  eidos,  resem- 
blance. Name  of  a  family  of  gas- 
teropods. 

TRO'CHI. — Plural  of  trochus. 

TRO'CHUS  (tro-kus}. — A  genus  of  gas- 
teropods. 

TRUNK.— The  body. 

TRUN'CATE. — Stunted,  cut  short  or 
abruptly  off  at  the  end. 

TU'BERCLE. — A  little  knot  or  pimple. 

TUBE'RCULATED.  —  Knotted  or  pirn- 
pled. 

TUBERO'SITIES. — Prominent  knobs  or 
excrescences. 

TU'BULAR. — In  shape  of  a  hollow  tube 

TU'BULATE. — Hollow. 

TUBULIBRANCHIA'TA. — From  the  Latin 
tubus,  tube,  and  bronchia,  gills.  An 
order  of  gasteropods  which  have 
the  branchias  lodged  in  a  tube 
(page  59). 

TUNICA'TA. — Name  of  an  order  of 
acephalous  mollusks. 

TU'NICATE. — From  the  Latin,  tunica, 
a  tunic.  Coated. 

TUR'BINATED. — Shaped  like  a  top  of 
pear. 

TU'RGID. — Swollen. 

TU'RRETED.  —  Resembling  a  tower 
with  turrets. 

TU'RBO. — Latin.  A  whirling  or  twist- 
ing. A  tribe  of  gasteropods  (page 
47). 

TURRITE'LLA. — Latin.  A  turret.  A 
genus  of  gasteropods. 

UMBILI'CUS. — The  aperture  or  depres- 
sion in  the  centre,  round  which  the 
shell  is  convoluted. 

UMBILI'CATED. — Having  a  depression 
in  the  centre  like  an  umbili'cus. 


114 


CONCHOLOGY.— GLOSSARY. 


U'MBO. — Latin.  A  protuberance  or 
boss.  The  round  part  of  a  bivalve 
shell  which  turns  over  the  hinge. 

UM' BONES. — Plural  of  umbo. 

UM'BONATE. — Bossed ;  having  a  raised 
knob  in  the  centre. 

UNARTI'CULATED. — Not  jointed. 

UNDA'TUM. — Latin.    Waved. 

UN'DULATED. —  Waved,  'having  a 
waved  surface. 

UNILO'CULAR.  —  From  the  Latin, 
unus,  one,  and  loculus,  partition. 
Having  a  single  chamber  or  com- 
partment. 

UNI'O. — Latin.  A  pearl.  A  genus 
of  mussels  (page  81). 

UNIO'NES. — Plural  of  Unio. 

U'NIVALVE. — Consisting  of  one  piece 
or  valve. 

UR'CEOLATE. — Swelling  in  the  middle 
like  a  pitcher. 

VAGI'NULA. — Latin.  A  little  sheath  or 
scabbard.  A  genus  of  naked  gas- 
teropods  (page  39).  It  is  the  same 
as  vaginu'lus. 

VALVA'TA. — A  genus  of  fresh-water 
snails  (page  48). 

VA'RICES. — Longitudinal  ribs  in  uni- 
valve shells. 

VA'SCULAR. — Composed  of  numerous 
vessels. 

VAU'LTED. — Arched  like  the  roof  of 
the  mouth. 

VE'NA. — Latin.     A  vein. 

VE'NOUS. — Relating  to  veins. 

VE'NTER. — Latin.  Belly.  The  most 
prominent  part  of  the  shell  when 
the  aperture  is  turned  towards  the 
observer. 

VE'NTRAL.     Relating  to  the  belly. 

VEN'TRICOSE.  Inflated ;  swelled  in 
the  middle. 

VEN'TRICLE. — A  little  belly.  A  part 
of  the  heart. 


VENERU'PIS.  A  genus  of  Cardiacea 
(page  85). 

VE'NUS.  A  genus  of  the  family  of 
Cardiacea. 

VERME'TUS.  A  genus  of  gasteropoda 
(page  59). 

VE'RMIFORM.    Worm-shaped. 

VE'RRUCOSE.  From  the  Latin,  verru- 
ca, a  wart.  Warted. 

VER'TEBRA. — From  the  Latin,  verier e, 
to  turn.  A  joint  or  bone  of  the 
back-bone  or  spine. 

VER'TEBRAL.  Relating  to  the  verte- 
brae. 

VERTEBRA'TA.  Name  of  the  first 
branch  of  the  animal  kingdom. 

VER'TEBRATE.    Having  vertebrae. 

VERTI'CULATED.     Whorled. 

VE'SICLE.     A  diminutive  bladder. 

VESI'CULAR.    Relating  to  vesicles. 

Vi'scus.  Any  internal  part,  as  the 
heart,  intestine,  &c. 

VI'SCERA.     Plural  of  viscus. 

VI'SCERAL.     Relating  to  viscera. 

VI'SCID.     Glutinous,  sticky. 

VI'TREOUS.  Resembling  glass.  A 
humour  of  the  eye  is  so  termed. 

VITRI'NA.  From  the  Latin,  vitrea, 
glass.  A  genus  of  fresh-water 
gasteropods. 

VOLU'TA.  Latin.  A  whorl.  A  genus 
of  gasteropods. 

VULGA'RIS.     Latin.    Common.   ' 

WHORL.  A  wreath,  or  turning  of  the 
spire  of  univalve  shells. 

ZONED.  Surrounded  with  one  or 
more  girdles. 

ZOO'LOGY.  From  the  Greek,  zdon, 
animal,  and  logos,  discourse.  The 
science  of  animals. 

ZOO'PHYTE.  From  the  Greek,  zdon, 
animal,  and  phuton,  plant.  An 
animal  belonging  to  the  fourth  di- 
vision of  the  animal  kingdom. 


NEW  AND  IMPORTANT  SCHOOL  BOOKS. 

TO  TEACHERS,  PRINCIPALS  AND  CONTROLLERS 

OF  SCHOOLS,  ACADEMIES  AND  COLLEGES 


We  take  the  liberty  of  calling  your  attention  to  a  Series 
of  Books  on  the  subject  of  Natural  History,  which,  in  the 
opinion  of  many  of  the  most  eminent  men  in  our  country, 
is  second  to  no  branch  of  knowledge  now  taught  in  schools. 
We  ask  your  attention  to  these  books,  because  we  believe 
them  to  be  superior  to  any  works  of  the  kind  ever  offered 
to  the  American  public.  They  are  small  in  size,  extremely 
cheap,  as  accurate  in  scientific  arrangement  as  the  most 
voluminous  works  on  similar  subjects,  and  in  every  respect, 
such  as  parents  and  teachers  would  wish  to  place  in  the 
hands  of  their  children.  In  confirmation  of  this  opinion  of 
the  worth  of  these  works,  we  respectfully  invite  your 
attention  to  the  following  testimonials. 

.     Very  respectfully,  your  obedient  servants, 

GRIGG  &  ELLIOT, 
JVb.  9  North  Fourth  Street,  Philad'a. 


These  books  have  been  introduced  into  the  Public  Schools  of  Pennsylvania 
and  Ohio,  and  no  doubt  will,  ere  long,  be  introduced  into  all  the  public  schools 
of  our  other  States. 

"We  regard  the  introduction  of  these  works  into  our  public  schools,  among  the 
highest  compliments  they  have  received ;  for  we  feel  sure  that  the  gentlemen 
who  constitute  the  committee  for  selecting  books,  possess  too  much  discernment 
and  general  knowledge,  to  pass  favourably  upon  works  of  inferior  pretensions. 
The  following  gentlemen  composed  the  Committee  for  selecting  books  for  the 
use  of  Public  Schools."  GEORGE  M.  WHARTON,  Esq. 

THOMAS  H.  FORSYTE,  Esq. 
GEORGE  EMLEN,  Jr.,  Esq. 
FRANCIS  LYONS,  Esq. 
JOHN  C.  SMITH,  Esq. 
Philadelphia. 

In  addition  to  the  following  flattering  notices  of  the  American  Press,  the  pub- 
iishers  have  received  upwards  of  one  hundred  recommendations  from  the  most 
prominent  professors  and  distinguished  teachers  of  our  country,  to  the  superior 
claims  of  these  works,  and  urging  their  introduction  as  Class  Beoks  into  all  the 
Schools,  Academies,  &c.,  throughout  the  United  States. 


FcTJSCHENBEHGER'S    SEZIIHS. 

FIRST  BOOKS 

OF 

NATURAL    HISTORY, 

IJR  SCHOOLS,  COLLEGES,  AND  FAMILIES. 

1.  ELEMENTS  OF 

ANATOMY  AND  PHYSIOLOGY. 

2.  ELEMENTS  OF 

MAMMALOGY, 

The  Natural  History  of  Quadrupeds. 

3.  ELEMENTS  OF 

ORNITHOLOGY, 

The  Natural  History  of  Birds. 

4.  ELEMENTS  OF 

HERPETOLOGY  AND  ICHTHYOLOGY, 

The  Natural  History  of  Reptiles  and  Fishes. 

5.  ELEMENTS  OF 

CONCHOLOGY, 

The  Natural  History  of  Shells  and  Mollusca. 

6.  ELEMENTS  OF 

ENTOMOLOGY, 

The  Natural  History  of  Insects. 

7.  ELEMENTS  OF 

BOTANY, 

The    Natural  History  of  Plants. 

8.  ELEMENTS  OF 

GEOLOGY, 

The  Natural  History  of  the  Earth's  Structure. 

This  interesting  series  of  books  has  already  met  with  the  most 
flattering  reception  ever  extended  to  any  work  issued  from  the  Amer- 
ican press.  Introduced  into  the  Public  Schools  of  Pennsylvania,  and 
in  nearly  all  the  first  class  seminaries  of  learning  in  the  United  State*. 


RECOMMENDATORY    NOTICES. 

" Ruschenberger's  Series  of  Books  on  Natural  History,  are  among  the 
most  valuable  and  useful  wo.ks,  for  the  use  of  Schools  that  have  ever  been 
published.  A  knowledge  of  Natural  History,  is  not  only  valmb'e,  but 
deeply  interesting;  and  no  one's  education  cm,  with  such  facili  ies  us  these 
works  afford,  be  considered  complete  without  it." — National  Intelligencer. 

"  These  are  the  most  valuable  additions  of  the  day  to  our  stock  of  School 
Books.  The  avidity  with  which  they  have  been  seized  upon  is  unprece- 
dented. Though  the  first  vol.  was  published  for  the  first  time  only  a  few 
months  ngo,  it  h»s  already  gone  through  its  fifth  edition;  the  second  is  fol. 
lowing  c!ose  upon  its  heels;  and  the  third  promises  even  to  be  more  popular 
than  either  of  the  other  two.  These  books  have  been  adopted  by  the  *  Uoyal 
Council  of  Public  Instruction,'  for  the  use  of  Schoo's  throughout  France. 
They  are  recommended  and  have  been  adopted  by  some  of  the  most  emi 
nent  teachers  in  the  United  States." — Southern  Literary  Messenger. 

From  '  The  Ladies'  Companion,  a  Monthly  Magazine."  June,  1842,— New  York. 
W.  Snowden,  109,  Fulton  Street. 

"RuscHENBKRGEn's  ORNITHOLOGY:  Grigg  &  Elliot.  This  is  an  excel- 
lent  book,  by  one  who  shows  himself  perfectly  qualified  for  the  task  he  has 
undertaken,  which  is  the  publishing  of  a  series  of  works  on  the  different 
branches  of  education,  for  .the  use  of  schools  and  colleges.  The  present 
Ifesue  is  a  general  and  synoptical  view  of  Ornithology,  one  of  the  most 
interesting  subjects  in  Natural  History,  and  will  be  found  of  great  service, 
both  to  teacher  and  student." 

"  This  is  a  compendious,  and,  as  it  seems  to  us.  a  judiciously  compiled 
treatise  on  Ornithology,  and  one  well  calculated  for  the  use  of  Schools ;  for 
which  object  it  is  intended." — N.  Y.  Courier  and  Enquirer. 

"  In  the  work  before  us,  the  plan  is  happily  carried  out.  In  its  small 
compass  it  embraces  an  immense  amount  of  useful  and  interesting  infor- 
mation."— Buffalo  Adv.  and  Journal. 

"  Ornithology. — This  is  evidently,  like  its  predecessors,  an  excellent  work 
of  instruction;  and  hai  been,  in  all  respects  well  got  up  by  the  publishers.* 
—Pennsylvanian, 

"  A  valuable  little  work,  and  is  divided  up  and  classified  admirably.  The 
glossary,  giving  the  derivation  of  the  names  of  birds,  is  of  itself  worth  the 
price  of  the  volume." — New  York  Aurora. 

"An  exceedingly  interesting,  and  very  instructive  book,  and  one  which 
possesses  special  attraction  for  young  ladies." — Baltimore  Sun. 

"RUSCHKNBERGER'S  SERIES  :  Second  Book. — A  highly  useful  and  instructive 
school  book.  Third  Book> — This  we  consider  as  decidedly  an  acquisition 
to  our  list  of  school  books,  the  subject  is  treated  of  in  such  a  plain  style  as 
to  be  adapted  to  the  simplest  capacity.  Altogether  we  think  the  above 
series  as  worthy  to  take  a  high  and  permanent  place  among  our  school 
books." — Buffalo  Democrat. 

"  We  wish  we  could  induce  our  teachers  generally  to  examine  this,  as 
well  as  the  earlier  works  of  Dr.  Ruschenberger ;  they  are  admirably 
arranged,  and  just  the  very  books  needed  for  schools.  The  work  before 
us  on  the  Natural  History  of  Birds  is  an  admirable  one,  and  no  teacher 
should  neglect  to  introduce  the  series.  * — Cincinnati  Gazette. 

•'  It  is  an  excellent  text  book  of  an  interesting  science,  comprising  much 
knowledge  in  a  brief  space,  presented  in  a  clear  style  and  with  lucid 
nrrangement.  Dr.  Ruschenberger,  who  has  already  achieved  a  high  charac- 
ter in  the  literary  world,  is  acquiring  additionnl  claims  by  his  exertions  i* 
Ihe  field  of  Natural  Science.—  Spectator,  Washington  City. 


RECOMMENDATORY    NOTICES. 

"  Ruschenberger's  Series. — These  volumes  are  constructed  upon  a  new 
and  admirable  plan,  combining  great  simplicity  of  arrangement,  with  a 
perspicuity  and  sententiousness  of  style  seldom  found  in  works  of  this 
class;  and  which  has  elicited  the  highest  encomiums  of  upwards  of  thirty 
of  the  leading  professors  of  the  country,  whose  opinions  have  again  been 
endorsed  by  most  of  the  public  prints." — V.  States  Adv. 

"The  developement  of  the  principles  of  classification,  is  among  the  very 
best  we  have  ever  seen.  Science  is  here  dressed  in  her  own  native  sim- 
plicity and  beauty,  so  that  the  philosopher  may  admire,  while  the  child  may 
acquire  it. — Medical  Reporter, 

44  Jt  is  a  choice,  and  well  digested  work." — Atlas. 

"  An  excellent  publication  adapted  to  the  youthful  mind,  and  a  great  help 
to  the  more  matured." — Mercury. 

"The  study  of  Natural  History  though  generally  neglected  in  schools, 
is  of  undoubted  use  :  the  present  work  contains  a  great  amount  of  infor. 
mation  within  a  small  compass,  and  properly  condenses  it  for  the  young 
mind." — N.  Y.  Journal  of  Commerce. 

"Ruschenberger's  Series. — The  subjects  are  tfrell  treated,  and  from  the 
exceeding  cheapness,  and  admirable  arrangfineiii'of  these  elementary  works, 
they  are  well  fitted  for  general  use  in  public  schools  and  academies."—* 
New  York  American. 

"We  do  not  hesitate  to  say,  that  this  is  the  best  work  of  the  kind  and 
dimensions,  that  has  even  fallen  under  our  notice.  We  hope  all  will  embrace 
the  first  opportunity  of  procuring  a  copy,  as  we  are  sure  they  will  prize 
it  highly." — Botanic  Recorder. 

"  A  well  digested  and  carefully  arranged  abstract  of  the  most  interesting 
parts  of  Natural  Science." — Philadelphia  Gazette 

"Admirably  adapted  to  convey  an  elementary  knowledge  on  the  subject 
of  which  it  treats ;  and  will  be  found  an  excellent  book  for  the  student." — 
Public  Ledger. 

"  Valuable  in  every  respect, — it  contains  a  vast  amount  of  information, 
condensed  into  an  available  form,  for  the  use  of  schools." — Spirit  of  the  Times. 

"Just  such  a  work  as  is  wanted  for  elementary  instruction,  in  this  pleas- 
ing  branch  of  science." — New  York  Evening  Post. 

"  We  regard  this  series  as  eminently  useful,  supplying  adequately  the 
instruction  in  natural  history  necessary  to  a  proper  school  education." — 
North  American. 

"  It  is  an  excellent  little  work  for  the  purpose  designed,  written  in  a  cl*  ar 
and  familiar  ^tyle,  and  will  not  fail  to  facilitate  the  studies  of  those  who 
wish  to  make  themselve-  acquainted  with  the  subject." — Saturday  Courier. 

"Admirably  adapted  for  elementary  instruction." — Saturday  Chronicle. 

"  We  have  great  pleasure  in  recommending  it  as  an  excellent  elementary 
manual  on  the  subject  " — Medical  Examiner. 

"  Ornithology — This  book  is  equal  in  merit  to  the  first  and  second,  and 
is  a  most  valuable  work.  It  is  intended  for  the  use  of  schools  and  acade- 
mies, and  we  would  call  the  attention  of  parents  and  others  to  the  series  of 
books  to  which  this  belongs,  assuring  them  at  the  same  time,  that  it  will 
answer  the  purpose  for  which  it  is  intended,  better  than  any  other  work  of 
the  kind  that  we  ever  saw,  or,  in  our  opinion,  that  was  ever  published  in 
this  country.  It  is  divided  into  questions  and  answers,  contains  an  exten- 
sive and  valuable  Glossary,  and  is  illustrated  by  eight  Plates ;  and  what  is 
more  the  price  is  so  very  low  that  every  person  can  aftord  to  purchase  it.— 
¥o)k  New  Era, 

4 


RECOMMENDATORY  NOTICES. 

It  has  been  justly  observed,  that  "  the  double  effect  of  the  study  of  Natural  Hiptoiy 
is  to  impart  certainty  to  the  mind,  and  religion  to  the  heart,"  and  the  Christian  no  less 
than  the  man  of  science,  must  rejoice  in  every  effort  to  throw  more  widely  open  the 
sublime  and  boundless  field  which  it  presents.  This  is  the  design  of  Dr.  Ruschenberger, 
in  a  scries  of  First  Books  of  Natural  History,  which  he  is  preparing  foi  the  use  ol 
schools  and  colleges. — Banner  of  the  Cross. 

The  series  have  met  a  demand  and  sale  in  France  almost  unparalleled,  and  the  words 
are  well  adapted,  not  only  lor  schools,  but  for  popular  reading  and  instruction.  This 
work  is  from  the  French  of  Edwards  and  Comte,  and  has  received  the  warm  commen- 
dation of  many  of  the  best  physicians  and  scholars  in  this  country — JV.  Y.  Eve.  Tattltr. 

It  is  highly  commended  by  the  very  best  authorities. — JV*.  Y.  Tribune. 

This  book  is  highly  commended  by  competent  judges,  and  we  therefore  give  our  so- 
lemn opinion  that  it  is  an  excellent  work. — Boston  Daily  Times. 

A  small,  but  very  valuable  work.— Boston  Evening  Transcript. 

We  have  examined  this  new  book  for  schools  and  colleges,  with  peculiar  gratificatioB. 
The  style  is  succinct  and  clear,  and  the  subject  illustrated  by  appropriate  drawings.  We 
should  be  glad  to  see  this  work  introduced  into  all  the  schools.  It  teaches  knowledge 
the  most  important,  which  has  been,  however,  strangely  overlooked  in  our  school  and 
college  system.  It  is  a  book  which  should  not  be  confined  to  seminaries  alone.  It  may 
be  used  with  advantage  by  all  individuals  in  society.  We  repeat,  it  is  in  all  respects  a 
most  excellent  work,  and  we  hope  will  receive  the  attention  and  patronage  it  meriu.— 
Brooklyn  Evening  vtar. 

A.  valuable  work;  we  have  read  it  with  profit. — JV*.  Y.  Mercury. 

We  are  highly  pleased  with  this  work.  For  elementary  instruction  in  families, 
schools,  and  colleges,  it  is  decidedly  superior  to  any  thing  of  the  kind  we  have  seen.  It 
gives  much  valuable  information  in  a  very  small  space,  and  in  style  it  is  generally  free 
from  obstruse  technicalities  It  has  already  received  the  highest  recommendations  from 
a  large  number  of  professional  men  in  different  parts  of  the  country  ;  and  it  must  have, 
we  think,  a  general  circulation.  It  gives  that  kind  of  knowledge  which  should  be  dif- 
fused  among  the  mass  of  the  people,  and  it  must  and  will  be  patronised  as  far  as  it* 
merits  are  known. — Ziun's  Watchman. 

This  is  a  fine  little  book,  containing  the  elements  of  much  useful  learning,  illustra- 
ted  by  anatomical  plates  of  the  human  figure,  its  organs  and  their  functions.  It  is  a 
highly  use-fill  work  to  the  student — indeed  to  every  citizen  it  shows  how  fearfully  and 
wonderfully  we  are  made,  and  what  slight  causes  may  derange  and  utterly  destroy  the 
complicated  machine. —  The  Olive  Branch 

A  very  useful  little  work.— JV.  Y.  Atlas. 

As  far  as  we  are  competent  to  determine,  it  may  safely  he  welcomed  as  an  important 
addition  to  the  means  of  elementary  instruction  in  natural  science, —  The  Friend. 

We  recommend  it  as  a  highly  instructive  publication. — JV*.  Y.  Times  and  Eve.  Star. 

This  is  a  most  valuable  work,  by  Dr.  Ruschenberger,  and  most  admirably  are  the 
plates,  representing  a!l  the  different  parts  of  the  body,  done.  It  is  cheap,  and  every  pa 
rent  .should  place  one  in  the  hands  of  their  children. — JV.  Y.  Herald. 

We  have  examined  this  little  volume  with  much  pleasure,  and  think  it  admirably 
adapted  to  the  purpose  for  which  it  is  intended.  Animal  Mechanism,  as  a  study,  hag 
generally  been  neglected,  except  by  the  few,  whose  profession  requires  a  knowledge  of 
it,  anil  who  have  time  to  spare  in  acquiring  that  knowledge.  A  prominent  cause  of 
the  neglect  of  this  useful  and  interesting  science  by  the  general  student,  is,  the  want 
of  a  suitable  treatise  upon  the  subject,  those  extant  being  too  voluminous,  technical, 
and  expensive  for  general  use.  The  little  work  before  us  is  happily  calculated  to  sup- 
ply this  want.  It  will,  we  think,  be  introduced  into  our  schools  and  colleges  as  a  text- 
book,  but  its  circulation  ought  not  to  be  confined  there.  Every  private  library  should 
be  considered  incomplete  without  it. — JV.  Y.  Mechanic. 

It  seems  to  us  to  be  well  suited  for  the  object  for  which  it  is  designed,  and  it  wiU 
ibtless  be  introduced  into  many  of  our  elementary  schools.—  The  .American  Journal 
the  Medical  Sciences. 


OPINION    OF    THE    PUBLIC    PRESS. 

"  Sach  a  little  treatise  is  just  the  thing  for  our  schools  and  academies  and 
no  tune  should  be  lost  in  introducing  it." — New  'York  Mirror. 

"  This  is  a  most  excellent  work,  and  we  would  most  respectfully  recom- 
mend it  to  our  common  school  tru  tees,  as  worthy  of  introduction  into  tha 
temples  of  learning  under  their  supervision." — New  York  New  Era. 

"  The  plan  and  arrangement  of  the  work  are  admirable,  and  eminently 
calculated  to  facilitate  the  progress  of  the  pupil. — We  recommend  it  to 
teachers  and  heads  of  families." — Philadelphia  Sat.  Chronicle. 

"  We  know  of  no  books  better  calculated  to  convey  elementary  instruction 
than  these,  and  heartily  recommend  those  which  have  appeared." — Brothet 
Jonathan. 

"We  cannot  too  earnestly  recommend  it  to  public  attention." — Cincinnati 
Enquirer. 

"  Decidedly  one  of  the  best  elementary  works  on  the  subject  with  which 
we  have  ever  met." — New  York  Lancet. 

"The  information  it  contains  is  at  once  lucid,  intelligible,  and  satisfactory; 
it  forms  an  ex?cllent  text-book  for  classes  in  schools,  and  cannot  fail  to 
infuse  into  the  young  mind  a  knowledge  and  love  of  Natural  History.  It 
is  concise  and  comprehensive,  and  must  if  adopted  in  seminaries  of  learning, 
be  exceedingly  useful  in  inculcating  a  correct  knowledge  of  the  elements  of 
Zoology.  The  plan  is  excellent,  and  must  be  found  eminently  useful."— 
Alexandria  Gazette. 

"  It  is  one  of  the  most  valuable  works  of  the  kind  we  have  erer  read.— • 
Such  are  the  books  we  like  to  see  disseminated  among  the  people." — New 
Orleans  American. 

"The  reputation  of  the  author  is  a  guarantee  that  the  work  is  a  good  one. 
On  examination  we  find  it  to  be  so.  It  is  an  admirable  compend  of  the 
subjects  of  which  it  treats: — we  should  think,  indeed,  that  it  would  attract 
the  attention  of  teachers,  both  from  its  cheapness,  and  the  admirable  manner 
in  which  it  is  armnged." — Cincinnati  Gazette. 

"  The  Second  Book: — this  number  treats  of  all  animals  that  in  infancy 
feed  on  the  rnilk  of  their  mothers;  from  the  human  being  down  to  the  mus- 
quito-catching  bat. — Like  the  "  First  Book,"  it  is  divided  into  questions  and 
answers,  and  a  glossary ;  and  is  illustrated  by  six  plates.  It  is  as  cheap  as 
dirt ;  and  contains  an  abundance  of  useful  information.  There  are  thousands 
of  persons  in  this  country,  and  millions  in  Europe,  who  do  not  know  that 
whales  give  milk." — New  York  Era. 

"We  do  not  know  a  more  useful  set  than  this  promises  to  be : — and  IS."—- 
New  York  Aurora. 

"  We  hesitate  not  to  say  that  it  is  a  valuable  work,  and  fully  entitled  to 
the  high  encomiums  bestowed  upon  it ;  taken  as  a  whole  the  work  may  be 
justly  regarded  as  invaluable  to  schools." — New  York  Standard. 

"  It  is  a  most  valuable  work,  and  one  which  we  believe  has  no  superior  in 
our  seminaries, — we  know  of  nothing  equal  to  it.  It  is  very  flatteringly 
recommended  by  the  most  distinguished  men  in  France  and  in  the  United 
States,  and  deserves  it." — New  York  Courier  and  Enquirer. 

Ruschenberger's  Second-Book  of  Natural  History. — "  This  is  another  01 
those  useful  volumes,  which  Dr.  Ruschenberger  is  so  beneficially  in  editing. 
His  former  volume  has  already  been  received  into  some  of  our  public  schools, 
and  we  hope  both  it  and  the  present  may  find  their  way  into  all." — American 
Medical  Intelligencer. 

The  present  work,  is  in  our  opinion  quite  a  desideratum,  and  abounds 
with  information  of  the  most  useful  and,  at  the  same  time,  most  necessary 
character,  every  parent  should  place  it  in  the  hands  of  his  children,  and  no 
public  instructor  should  neglect  to  give  it  a  place  in  his  academy. — Philn 
Spirit  of  the  Times.  6 


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General  Library 


•. 


C 


SERIES, 


FIRST    BOOKS 

OP 

NATURAL   HISTORY, 

FOR  SCHOOLS,  COLLEGES,  AND  FAMILIES. 

1.  ELEMENTS  OF 

ANATOMY  AND  PHYSIOLOGY. 

2.  ELEMENTS  OF 

MAMMALOGY, 

The   Natural   History   of  Quadrupeds. 

3.  ELEMENTS  OF 

OB  NIT  H  0  L  0  G  Y, 

The  Natural  History  of  Birds. 

4.  ELEMENTS  OF 

}TEBPETOLOGY  AND  ICHTHYOLOGY, 

The  Natural  I  f  Reptiles  and  Fishes* 

VTS  OF 

CONG  II  0  L  0  G  T  , 

The  Natural  History  of  Slit;  Us  a  id  ~;fc  Ju<ea. 

6.  ELEMENTS  OF 

ENTOMOLOGY, 

The  Natural  History  of  Insects. 

7.  ELEMENTS  OF 

BOTANY, 

The   Natural    History   of    Plants, 

ELEMENTS  OF 

G  E  0  LO  GY, 

The  Natursal  Fiistory  of  the  Earth's  Structure. 

:  ••.-•  dread]  •  ith  'he  most  fianer- 

•  .  •     issued  I     m  she  American  press. 

>;.  a,  and  in  nearl'/  all  tho 


